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How to Clean or Replace the MAF Sensor for VW or Audi


I'm an online writer and proud owner of an Audi 1.8T. My articles focus on helping Audi and Volkswagon owners handle DIY projects.

Mass airflow (MAF) sensor

Mass airflow (MAF) sensor

The Benefits of Cleaning Your Mass Air Flow Sensor

The more oil and dirt that accumulates on your MAF, the worse it serves its purpose. The dirtier it gets, the less accurate the reading it sends to your ECU (computer). These readings can cause lower gas mileage and a small loss of power.

Cleaning your MAF will not only extend the life of the sensor, but it will also help keep the power level and gas mileage where they should be. So if you feel a lack of power when you hit the gas, or have noticed a change in your miles per gallon, the MAF sensor is the best place to start on your Volkswagen or Audi.

Parts and Labor Cost from the Dealership

A new MAF sensor from the dealership can cost anywhere between $80 and $150, depending on your car's make and model. The labor cost will add on another $150, as VW/Audi estimates the labor time needed as an hour and a half.

Recently, my new GTI needed a new MAF for emissions, as the old sensor was completely dead from the previous owner running the car with no air filter. I bought a new one on eBay for $40 that even came with a 90-day warranty; it has been six months and I've yet to have a problem with it. So if you're willing to trust an eBay product, that is also an option.

Doing this job as a beginner will take you around 30 minutes if you are replacing the MAF sensor, or around two hours (including drying time) if you decide to clean the sensor and put it back in. No special tools are needed for the job. It is very straightforward and easy enough for anyone to accomplish.

So why throw away $300 instead of doing thirty minutes of work?

Testing Your MAF Sensor

If you are already showing a "check engine" light on your dash, or you think you are feeling the symptoms of a bad MAF, here is an easy way to check the problem.

  1. Unplug the MAF harness
  2. Drive around

Yep, that simple. If you unplug your MAF and your car all of a sudden perks up, then the MAF is more than likely the problem, and cleaning the sensor is a great place to start.

Warning: If your check engine light is not already lit up when you try this test, unplugging the MAF sensor will cause it to illuminate. You can easily reset the light by unplugging the negative terminal on the battery for ten seconds (which is what I would suggest), or driving for sixty miles so the car can cycle.

If your check engine light is already on, then this is a great test to try, but before you try it, head to your local auto store and get a free scan. If they tell you that it is an oxygen (O2) sensor, then do this MAF test anyway, because an OBDII scanner can give false codes on VW/Audi and this test is a simple way to eliminate other causes for your check engine light.

Tools you'll need to remove and clean a mass airflow (MAF) sensor.

Tools you'll need to remove and clean a mass airflow (MAF) sensor.

Tools and Parts for the Job

  • Philips-head screwdriver
  • Vise grip or pliers
  • 91% isopropyl alcohol (rubbing alcohol), or MAF cleaner
  • 2 trim replacement screws
  • Gallon-size ziplock bag

The tools needed for this job are very simple. You should have most of them in your garage or tool drawer.

One tool that I have not listed is a specialty "tamper proof" five-star Torx bit made by and for VW/Audi. I've not listed it for three reasons.

  1. This tool is incredibly hard to find, so it is not worth the price or hassle of ordering it from a VW/Audi dealership.
  2. The screws involved can be replaced with Philips-head screws for future convenience.
  3. These screws can be removed with pliers and once they're out you'll never have to deal with them again!

NOTE: Some MAFs use a 6-point tamperproof screw. If that is the case you can easily find a bit or screwdriver for those screws at any hardware or auto store for cheap.

The chemical that is used to clean the MAF sensor is completely up to you. There is a large variety to choose from at your local auto parts store, or you can use rubbing alcohol from the grocery store for about a dollar. I always use rubbing alcohol and have never had a problem. It cleans, dries quick, and is cheap. So for the cleaning part of this DIY, I will be using common 91% isopropyl alcohol.

Screws to replace the 5-point Audi Torx screws can be bought at any auto shop. I purchased a small pack of #10 trim screws from AutoZone for $2.29; they look just like the stock screws but with a Phillips-head tip. Another option is to just re-use the 5-star screws and put them back in the same way you took them out.

How to Remove the MAF Sensor and/or Housing

1. Unclip the harness connected to the middle of the MAF. The clip can be removed using your thumbnail. If it won't pop up, try a small screwdriver. Be gentle so you don't break the clip. Once you hear the clip pop, wiggle the harness off of the MAF. (All of the harnesses use the same type of clip, so once you learn how to release one, you can use that technique for coils or any other harness that needs to be taken off for repair. Here's how to replace a VW/Audi harness clip if you break it.)

2. Here you have a choice: you can either remove the sensor from the housing or remove the housing and sensor as a unit. If you still need to remove the 5-point tamperproof screws, I recommend removing the whole unit. Next you will need to remove the two Phillips-head screws connecting the MAF to the air box (on the right side of the MAF). Once those screws are out, disconnect the other side of the MAF from the turbo inlet pipe. Most VWs and Audis use pinch hose clamps, so use your pliers to squeeze the clamp open and slide off the inlet pipe. When putting the MAF back on, you can use a screw-type hose clamp to save yourself some hassle next time.

Slide the wire harness off of the MAF Sensor. Loosen the hose clamp on the left and the two screws attaching the MAF to the air box.

Slide the wire harness off of the MAF Sensor. Loosen the hose clamp on the left and the two screws attaching the MAF to the air box.

 Push the large hose (TIP) off of the MAF housing and you can now completely remove the MAF from your car.

Push the large hose (TIP) off of the MAF housing and you can now completely remove the MAF from your car.

3. If you are choosing to remove the sensor only (which I recommend if you have regular 6-point Torx screws): Unscrew the two bolts in front of and behind the harness plug. Gently wiggle the sensor out of the housing. Skip down to step 6.

4. Once the housing unit is free, take your vise grips or pliers and pinch the sides of the screw connecting the sensor to the housing. (It can be a pain in the a**, but once you're done and replace those bolts you will never have to do it again). Grip it, turn counter-clockwise, re-grip it, and repeat till both screws are out.

5. The sensor is in nice and tight so wiggle it out of the housing.

Holding the MAF grip the sides of the screw tightly turning counter clockwise.

Holding the MAF grip the sides of the screw tightly turning counter clockwise.

Wiggle the sensor free of the housing.

Wiggle the sensor free of the housing.

6. Once you wiggle the sensor out, put it in your ziplock bag and grab a beer. Victory is yours. The hard part is over (if you even want to call that hard!).

7. Fill that bag with rubbing alcohol and shake, shake, shake! If you are dealing with the sensor by itself, and not the housing, you can use a smaller bag with less alcohol, and use q-tips to clean off any left on residue. That's why I recommend taking the sensor out of the housing.

8. Once you're satisfied the sensor's clean, allow the parts to completely dry before re-installing and starting your car.

9. If you were dealing with the 5-point Torx screws, you can put the housing back in using the same method of using pliers on the sides of the screws, or you can replace the screws with the trim screws I mentioned above.

Time for the alcohol bath.

Time for the alcohol bath.

Volkswagen and Audi MAF Part Numbers

MAF Sensor Part NumberEngine CodeCar Model

06A 906 461 L


Audi A4, A4 Quattro 01-05, Audi TT, Audi Quattro TT, All GTI, Jetta 1.8T (AWP, AWW engines)

06C 133 471 A


Audi S4 00-02 2.7T, Audi A6 Quattro 01-04 2.7T & 3.0, Audi FWD 02-05 3.0, A4 Quattro 02-05 3.0

06A 609 461 M


Audi TT 225

07D 906 461 X


X R32, W8 Passat, Touareg 3.2 V6, Audi 3.2TT

06A 906 461 A


2.0L Golf, Beetle

If you can add to my list, or have any corrections, please post a comment or send me an email.

K&N Filters, CAIs, Short Rams, and MAFs

This is always a huge debate.

Do K&N filters ruin mass air flow sensors?

In my opinion, yes and no. An over-oiled K&N filter will definitely coat, and, in the long run, ruin your MAF sensor, costing you a $100-$200 part. But a lightly-oiled K&N filter lets more air travel through your engine while still trapping dust and dirt particles, with no harm at all to your MAF.

I have used K&N filters in stock air boxes, short ram air intakes, and regular cold air intakes (CAIs) and I have never had a problem with them ruining an MAF sensor. To avoid problems, take one simple step: clean your MAF every 5-10 thousand miles. That preventative maintenance should be done no matter what type of filter you are using, oil or paper.

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.


Writen4u (author) on September 13, 2019:

Hi Junior,

That is a good question. The dealer and all mechanics quote some "labor book" that gives an estimated time frame for the repair. I have no idea if these time frames come from the manufacturer of the car or what. They all will have the same estimate for the time frame, the hourly cost of labor between mechanic and dealership will vary.

If you call a mechanic or dealership they will charge for labor off the "book" price. Whether or not they can get it done in 5 minutes. Maybe a mechanic will chime in and give us some insight. All I know is an old neighbor of mine was a mechanic and he was paid off of "book" price so he could log 100 hours in 40 dependent on the time it took him to do repairs.

So no, they do not "pad" the labor, they just use the "book" to screw you over.

Thanks for the comment.

Junior Ganymede on September 06, 2019:

The article states:

--VW/Audi estimates the labor time needed as an hour and a half.

--Doing this job as a beginner will take you around 30 minutes if you are replacing the MAF sensor.

Does a dealership really pad its labor charge that much?

Writen4u (author) on April 03, 2019:


That is a good question. I believe if you read step 3 you would of had your answer.

I have never seen an MK4 with a 6 point torx security bit, only the five star. Also most cars have a stock air-box butted against the maf. Trying to grip on to a 1mm screw flange from the top vs the sides will make a world of difference.

For the time savings of undoing two additional screws and a hose clamp I would just recommend removing the whole housing that way you can wash it out as well.

Lew to go.. on November 18, 2018:

Why can't your remove the sensor element only to clean, instead of having to take the whole sensor housing out of the car?

Liam on October 05, 2017:

@ Brandon; I have heard swapping a battery might do the trick, if there is another suitable one close by....

Brandon on July 14, 2017:

We had a rough idle and drive in our car and the codes said mass air flow sensor, replaced the damn thing yesterday and still rough. Anyone got any ideas?

Marie on May 09, 2017:

Hubby got me an EOS. Last owner drove it with regular unleaded instead of supreme. Engine light is on when we got the car. Would cleaning the MAF help?

lneil@hotmail.com on April 22, 2017:

Thankyou. Your answer is perfect. I like to check before I do maintenance even though I think I know how. When one does not do repairs for a living, one gets rusty.

Writen4u (author) on February 19, 2017:

Hi Danny.

A little late on the reply but for future searchers, some mafs have resistors and some do not, I believe the 2.slow has the resistor as it works as the temperature sensor (IAT) whereas the 1.8t has the temperature sensor plugged into the throttle body.

danny on December 13, 2016:

hi would you by any chance know what resistor should be on the maf ive just took my sensor oout as the car seems to be a bit laggy and there is no resistor is it 1k ohm .5w or 10k ohm .5w

Writen4u (author) on October 05, 2016:

Chris, I do not really know about the 2010 model or what engine you have but if cleaning the maf does not help it may need to be replaced. I would recommend getting your car scanned with a proper vag-com so you know the codes are accurate as generic scanners can throw false code. Also pressure check the system as you likely have a vacuum leak somewhere in your system (i'm guessing around your breather/PCV hoses or SAI hoses) among other spots. But only a guess.

Chris on September 19, 2016:

I have the codes in front of me now:

P0441 Evaporative emission system incorrect purge flow

P1827 System too lean at idle bank 1

P2015 Intake manifold runner position sensor/switch circuit range/performance bank 1

P2279 Intake air system leak

I am hoping this does not warrant yet a 3rd intake manifold switch as I fear this one will not be under warranty. Switching the MAF would be a whole lot easier..


Chris on September 19, 2016:

My 2010 GTI recently started displaying a MIL and a quick Autozone scan mentions errors of the intake running lean and a performance issue (I do not have the exact codes in front of me). The computer recommended a new MAF, so I cleaned the whole thing according to your steps and disconnected the battery.... However the light is still there.

The car runs fine with a few minor hesitations at low speeds which seem to go away. I unplugged the MAF harness to see if there was a difference in performance and didn't notice anything different - although there were no hesitations.. But could have been due to car being warned up.

Could it be that the MAF needs to be replaced completely? Also note that I had to have my intake completely replaced 2x since owning the car.. Once at 25k and another at near 100k. I have 153k miles on the car now running the same MAF I believe.

Any help would be appreciated! Thanks!!

Writen4u (author) on April 17, 2016:

Hi Peter,

Personally I have never used it, but I don't see how using denatured alcohol would have any adverse effect compared to rubbing (isopropyl or ethyl) alcohol. I'm currently pulling a rich code myself and if I have some handy in the garage I will try it on my maf.

Peter S. Kim on April 15, 2016:

Has anyone tried this using Denatured Alcohol instead?

Steve S on April 06, 2016:

Hi mate

Reading through this has made me glad to be alive again! haha.

I've bought a VW Caddy 2007 Sdi (first one!)

Now where to start?

I bought the van, it started fine, drove approx 150 miles home and then it failed to start without constant turning of the key. Once started it was fine, until it decided to cut out every now and again.

I booked it in for a quick service and change the oil, oil filter, air filter and fuel filter. after collecting it from the garage, it was smoking from the exhaust (grey smoke). I continued to drive it on a planned holiday to France and clocked up 1200 miles. On my return after countless problems, it began to miss fire, not start and run like a pig with more smoke than an Australian forest fire! After 5/6 so called mechanics have filled my ears with garbage, finally a nice chap got his hands dirty and convinced me it was the Injectors, so I got them all replaced at a costly sum.

Now.. the van is starting fine and running fine almost. But on tick over, it is now juddering slightly until you slightly depress the accelerator and raise the revs, but also BLACK smoke has now appeared!! (still very frustrated and almost on the verge of a divorce, through constant talking about this to my Mrs.) lol.

Please help. Could this be as simple as cleaning the MAF.

I look forward to your reply and apologies for the novel.


Steve S

Writen4u (author) on March 19, 2015:

Hi SteveyC, the terminal post on the sensor are for the intake air temperature. My 1.8t has the IAT separate from the maf and it is located on the trottlebody, whereas my 2.0slow has the resistor built directly into the maf. It all depends on the car and engine. So if you look at your throttle body you will see a 2 wire plug, that sensor is held in with a 5mm bolt that is your IAT you can pull it out and clean it like your maf as well. Hopefully that answers your question. Thanks for the comment.

SteveyC from Selby on March 15, 2015:

Hello and thank you for the great advice in your column. I've not taken the car for a run run yet, however I've noticed that it is idling a little faster so that seems like good news. The reason I'm getting in touch is that having scoured though the pages of comments and your information I can't see anything regarding what appears like terminals for a resistor at the side of the MAF sensor, there doesn't appear to have ever being one in there and I just wanted to know what's it for...? Thanks again for a great post.

Writen4u (author) on January 31, 2015:

I'm glad it at least helped your gas mileage. I guessing a celebrate light is a check engine light? You will need to get the car scanned as it could be hundreds of things as to why it is still lit up. Turn the key to the on position (position before actually starting the car) for the throttle body. The door lock module could be going bad. The lock modules before 2003 were pretty prone to failure. Good luck.

Eddie on January 24, 2015:

Thanks for the great page. I just finished cleaning my MAF after being told that I needed a new one. I was skeptical it would work because when I pulled my MAF it looked like it was right off of the assembly line. I talking show room clean. So I soaked it as instructed and reassembled the thing. The whole time it was soaking the battery was disconnected so that the computer would reset. So I took it for a spin but the celebrate never went out. Now I'm not saying that this was a failure, in fact I believe that you have solved my problem. I say this because even though the celebrate is still on, my gas mileage is now awesome. This is based off of the displayed mpgs on the dashboard. Before I cleaned my MAF I would never see readings above 15 to 17 mpgs. Now after taking the car out for a quick test drive I'm clocking 25 to 28 mpgs. So something happened obviously. So now do you have any recommendations as to the celebrate light? Do I need to go get it reset or will it just go off on its own?. Keep in mind that I had the battery disconnected for an hour or more. Also, when I have the door open and the key in the on position, the throttle body does not reset. But the interior lights don't come on with the door open either. It is a 1999 Passat 4 cylinder. Thanks again for a great post.

Powerline Auto Recyclers from Seymour, MO on September 25, 2014:

Just a note to the several questions, do not use brake/carb cleaner on your MAF. These chemicals break down plastics and will coat the diode inside the MAF assembly which will throw off the reading.

If you cannot get electrical or MAF cleaner, and you must use brake/carb cleaner, ensure it is non-chlorinated.

Writen4u (author) on March 11, 2014:

My 1.8t actually has a bad map sensor right now. I tried cleaning it but it made no difference. I think with maps once they're gone they're gone, but you could always give it a try if you have a lot of oil running through your intercooler.

Awais on March 11, 2014:

Great write up. Does MAP sensor cleaning similar?

Writen4u (author) on November 19, 2013:

And still goin' strong!!

Sage on November 17, 2013:

Wow. I just checked in on this site and noticed that you have been commenting to people since there years back. And now, the latest comment was just 2 months ago. That's crazy. Just thought I'd say that.. Hehe. And yes I've replaced my MAF so that's how I found this page.


Writen4u (author) on September 08, 2013:

One of my cars has had a cheap one in it for over two years now, and my other car has had one for over a year with no problems.

andy on September 02, 2013:

No no no cheap Maf over a bosch u will have nothing but trouble

Writen4u (author) on June 22, 2013:

Glad my articles helped, now if I could only figure out what's wrong with my GTI!!

Moses Mvula on June 21, 2013:

Hi, what a surprise,

I don't know what to say or how to say it. My vehicle is a VW Golf GTi,1.8T 2001 model. I had a number of problems before and i dont remember how many Mechanic i have been too of late and costed me lots of money, and now was almost thinking of selling my Black Beauty. So my last option was to follow and every step i learn t on www.writen4uhubpages.com, I cleaned the MAF, which was very dirty, cleaned the TB which was extremely dirty, cleaned the IAT Sensor which had a lot of oil stuck on it, i also cleaned the FPR, and also changed the Con Paper Air Filter and replace spark plugs and used BOSCH Super plus FR 7DPP+ GERMANY +24 , and also change the Engine Oil, vw Fuel Filter. Guess what? The car moves extremely smooth than ever before and has improved fuel economy . On one single Full Tank tank i am able to do 980km with the AC on, almost 1000km, Amazing.

Many thank to Hud DIY Auther for sharing wonderful ideas on internet, something which has saved me lots of money. This site is really Awesome

Writen4u (author) on May 10, 2013:

Try and get it scanned, if it is running better you may have fixed one problem that created another. You really should not have any dirt or sand past your air filter.

If it is your maf that shows up bad after a scan, well sometimes the only thing you can do is replace the maf. On a side note, if you are a VW purist make sure you spend the $150 for the bosch maf from the dealership, if you just want your 2000 passat to run, get a $30-$50 Chinese maf from ebay. Same maf, just does not come with the bosch stamp.

Jonathan on May 09, 2013:

Hi there! glad I stumbled upon this how to page.. I tried cleaning my MAF sensor in my 2000 VW Passat as well as taking out the entire air box and the hoses to clean out all the dirt and sand. After putting it together my car seemed to be running better but 86 miles later my CEL and emissions workshop came back on. I had read somewhere about cleaning the MAF sensor with denatured alcohol rather than rubbing alcohol due to higher alcohol content so i'm going to give that a try.. anyways why do you think my light came back on? Could the sensor be trash? It is the original sensor and I have 140,000 on the car.. Thank you!

ralphg on January 14, 2013:

Thanks. Worked great. Saved me 150 dollars. Took about an hour take a beer or two.

Writen4u (author) on January 03, 2013:

Ryan- They have wire repair kits with the pins attached and you only really need about a foot of wire. Cut off the old wire near the plug, get the pin out, replace with your new pin and crimp the wires back together. If you are actually replacing the whole wire back to the ECU I think your only choice would be to pull the wire and buy the appropriate size from an auto parts store or a used engine harness from someone and pull out the wires you need.

Ryan on January 01, 2013:

Does anyone know the size of the MAF wiring harness? I need to replace mine and the audi dealer said they need the correct size of the wires as they are different for every car?

jiggy on December 02, 2012:

my issue ended up being a bad EVAP valve, $40 part. Lesson, clean you MAF and replace EVAP every 75,000 miles.

Fred on November 28, 2012:

Great instructions. I have a 2008 Audi A6, when I first start it in the morning or when it has been parked for a while and start to drive, it jerks for a minute and then runs smoothly. I also tried just reving the engine when I first start it in the morning it sounds like the engine is hesitating for a few minutes. I was wondering if this has something to do with a dirty MAF before I start working on cleaning it. Thank you for your help.

Writen4u (author) on November 26, 2012:

I'm not sure about the MKIII, but you should probably get your car scanned by someone with a vag-com. Those generic scanners can give false readings on our cars. I was told once I had a bad 02 sensor and it turned out to be the maf. Hopefully a good cleaning will clean the fault and you'll have your answer.

Everything online says p0113 it your Intake air temperature sensor. some mafs have them built in (little resistor on the maf sensor) and some are separate sensors screwed into the intake manifold. on the 1.8t I know it is separate and I don't have my 2.0 here to check and see if it is the same. So you can also see if you can find yours and clean it as well. They are only around $10-20 to buy a new one (a lot cheaper than a maf).

ben on November 26, 2012:

I went to autozone to get the code on cel it gave me p0113 now I was told this was air intake temp sensor this is on a mk3 jetta 1999 I was told this was the MAF sensor is that true or is it something else , I am now cleaning the MAF hoping that this is the problem

thank you

jiggy on November 22, 2012:

Thanks for this. My A4 has been to the dealer 4 times to fix a rough idle. Unfortunately I just had to pay for new O2 sensor which didn't fix the problem. Once in a while I could smell eggs when shutting down the car, they wanted to swap the Cats next at $2300. Today I cleaned the MAF sensor and the problem is fixed. Now I just have to find a way to get a refund for the O2 work that was done.

Writen4u (author) on October 04, 2012:

Why not take the ten minutes and clean it and see if it helps? Nothing is going to help if you have vacuum leaks.

What are you scanning your car with? Did you pressure check it?

david chapman on October 02, 2012:

sorry 03 20th AE GTI

david chapman on October 02, 2012:

my car ( 03 starts very roughly on cold/chilly mornings. the CEL is on, and i have a no name CAI. i have had the code checked a number of times and it keeps coming up the same, mass air volume. woulld cleaning the MAF help these problems?

thehaggis on August 25, 2012:

Cheers mate, great walkthroughs, I'm currently working my way through them :-) thanks again.

Joel Portugal on June 23, 2012:

Thanks for that DIY. Is very useful for me. My car is a Golf mk5, so it's very identical and easy.

To remove the MAF sensor was very easy. I didn't need anything more than a very small and simple screwdriver. I held the screwdriver between the little notch and 6 points of safety and was just unscrew! Very simple actually. I don't need do break/replace anything ;)

Writen4u (author) on May 24, 2012:

Thanks for the tip Ravi. I'll have to try that next time.

Ravi on May 24, 2012:

Great write up with nice explanation and pictures.

I tried this earlier today and it worked for me.

Just to update on removing the sensor, on my Audi A4 B5, the sensor had 2 6 point security screws. I used a small flat head screw driver to break the little notch inside the star. Breaking it out basically turns this screw to a regular torx. So I need to replace the screws.

Ben on April 25, 2012:


Just wanted to say thanks for a great how-to - I'd been having problems with my 2001 Golf for the past few months... and your post was real helpful and it worked a treat. I also followed your how-to for replacing the temperature sensor... that was even easier!

Cheers mate,

Ben (Melbourne, Australia)

Tolli on March 09, 2012:

Had to give props on this one. A $1 bottle of isopropyl alcohol and about 40 minutes is all it took for me to get back smooth acceleration and power in my Audi TT.

Chad on March 07, 2012:


I have a 2002 VW Jetta, and it won't start. I had a diagnostic run on it a few weeks ago for something else, and the MAF was one of the things that came up. I didn't think anything of it, but now I think it's biting me in the ass. I'm about to clean the MAF now with the rubbing alcohol. Let's hope it works. Great writeup.


Writen4u (author) on February 23, 2012:

You can use rubbing alcohol from the grocery store. It is sold everywhere, It is what is used in the diy.

Ikenna on February 23, 2012:


i want to clean my MAF, but i cant find MAF cleaner here in Nigeria. The only solvent in Nigerian Markets is Carburretor cleaner. Is it safe to clean with carb cleaner. What about fuel (PMS). Is it also safe to clean with it? My 505 V6 MAF is so dirty and contaminated with oil that i fear if is not completely dead. But i want to clean it first and see if it can still work. The car has been hard starting, stumbling, running rich & emitting black smoke for a very long time now. I have checked & replaced nearlly all the sensors or components that can cause such symptoms, but the problem persisted. I even replaced the injection ecu yesterday, but its still doing the same. But since my MAF is very very dirty with dirts and oil, i believe it might be the culprit. But what to clean it with is now the problem. Only carb cleaner is what is available here. So can PMS (fuel) do the MAF cleaning work safely?


Writen4u (author) on January 06, 2012:


If the connections to the maf sensor are corroded and broken and that's what they are replacing, then yes you could do that on your own. You would have to buy a wire repair kit from VW and a new connector (the part number for the connector should be in my (replacing wire harness connectors DIY)). As for the wire repair kit you should be able to find it online or at the dealership parts counter. It should be a pretty easy job for a novice

Leah J on January 04, 2012:

My CEL has been on for a couple of weeks, dealership finally found the issue to be MAF sensor shorted out and the connections are corroded. Totally cost for parts & labor $784, ouch. Hopefully I'm in the right place asking these questions. I'm a serious novice at car repair but could I replace the MAF myself for cheaper than the dealership? As for the connectors, I have no idea what that means. Would really appreciate any help you can provide, you've done a great job for others!

shakeel on October 10, 2011:


I wanted to know if it is safe to use a hair dryer to dry the MAF sensor after cleaning it with alcohol.

shakeel on October 10, 2011:

Thanks a lot.

Writen4u (author) on October 10, 2011:


Go ahead and use ethyl alcohol, it will clean it the same. Unhooking the maf is more for testing to see if it is the problem, I wouldn't recommend just leaving it unhooked while driving it around. I don't think it would cause any short term problems but long term your car will start running rich/lean and the ECU will not be able to properly calculate how much gas it should be spitting out.

shakeel on October 10, 2011:

I disconnected the wiring of the MAF of my vw bora 1.9 TDI this morning and now the car is running much faster than before and is feeling much lighter. Before I had to accelerate up to 2500 rev/min in the second gear in order to activate the turbo. Now the turbo is on as soon as I start driving on the first gear.Is it safe to leave the MAF disconnected and for how long?

shakeel on October 09, 2011:


I have a vw bora year 2000. I want to clean the MAF sensor. But where I live I cannot have the isopropyl alcohol nor the maf cleaner. Is it possible to clean it with a carburetor spray cleaner or ethyl alcohol or do you have any other suggestions? Thanks

Terry on September 30, 2011:

Thank you

Writen4u (author) on September 30, 2011:


I have an idea, Google.

First off the dealer ripped you off by $480 to change a $20 air filter and up your idle speed.

Second this is an article on cleaning MKIV Maf's not a problem solving forum. If I were you I would post your question (with a lot more detail if you want help) on vwvortex, or audizine, Hope that helps for a place to start.

Terry on September 28, 2011:

We have a 1990 V8 Quattro. It starts and runs fine, when you try to back it out of the garage it wants to die out. It runs nice out on the road, just runs poorly at idle speeds in gear. Took it to a local dealer who changed the air filter and turned up the idle speed for $500 (very bad experience)any ideas on this one????

Writen4u (author) on August 21, 2011:


Glad it helped. With all these dealer fees I'm saving people I need a way for people to send me a dollar! I'd be rich by now!!

Ken on August 20, 2011:

I followed this directions, and I am pleased to report that my MIL warning light has gone out and I can now pass my admission test. The only variation I did was I did not have to remove the housing as I was able to remove the MAF sensor without doing that.

I can not thank you enough for this information as I was going to take my car to the dealer before I discovered this blog. Considering parts and labor, you likely saved me $400. Thank you!!!

Ken on August 18, 2011:

Thank you, thank you for the quick reply. I'll give it try this evening.

Writen4u (author) on August 17, 2011:

Hey Ken,

If you are taking the sensor out of the housing you will be able to see the dust and oil build up on it. So for time really your just trying to give it a good rinse like you would swishing listerine around in your mouth. If your shaking the whole housing around in alcohol just give it a good shake for a minute or two and most of the residue should come off.

As for drying just shake the sensor of any remaining alcohol and it will be completely dry in a few hours. Alcohol dries very fast, you can also rub the housing and screen down with a towel to get off any stuck on oil.

Ken on August 17, 2011:


I just discovered these great instructions and am looking to try this on my 2006 VW Touareg in the next couple of days. Question about the cleaning in alcohol and drying. How long should you leave the sensor in the bag of alcohol and how much shaking should be done? How do you recommend allowing the sensor to dry, naturally over night or with a hand towel.

Thank you so much for this great resource

Writen4u (author) on July 27, 2011:


Google maf sensor location and your vehicle, you will see a picture. It is located in the front left of the car under a plastic cover.


I have no knowledge of the mk3 gti. On a mk4 the car still starts and runs without the maf even plugged in. If you disconnected your battery to reset the fault code, maybe you forgot to reconnect it properly.

nemo on July 24, 2011:

Hi I have cleaned my maf in a golf 3gti, now the car adoesnt want to start, everithing was connectd right, could it be a setting?

Daniel on July 04, 2011:

I was looking on the left side of the engine under the plastic covers at the air intake that goes to the engine, but still I could not identify the MAF sensor. I will keep checking this post for when you can locate the exact location. Thank you for checking it out for me.

Writen4u (author) on June 13, 2011:


If you have the 1.8t A4 your maf should be more to the left side of the engine bay next to your air intake, as opposed to the right side on a VW 1.8t. If I see my neighbor outside I'll take a look at his car for an exact location.

Try removing any of those plastic covers near the air box and it should be in that vicinity..

daniel on June 12, 2011:

Thank you for great posting. Where is exactly the MAF sensor located in the 2001 Audi A4 Quatro? I have looked all over the internet, but I was not able to find it. I wish I could find the picture pointing to the MAF sensor. I need to clean or replace it because of the P0171 code and my car won't pass emission test because the O2 sensor is not ready. And I have already replaced the O2 sensor myself and mechanic replaced the hose and pipes.


Writen4u (author) on June 05, 2011:


Sorry For the late reply.

Have you tried scanning the car with vag-com and seeing if it is causing any codes that are being stored without causing a check engine light? I don't know what engine you have but if it's the 1.8t maybe it could be your n75 valve is on it's way out, also check for vacuum/boost leaks and change your spark plugs if they are old maybe it's missfiring. Besides for that I don't know what else to recommend. Maybe somebody else will chime in with a helpful hint.

Marnie on June 01, 2011:

Thanks for the great instructions!

I have a manual 2000 Jetta GL. The car has been "bucking" or "jerking" while accelerating. It occurs in all gears and at all speeds. From what I have read online, it seemed like a dirty MAF might be the cause by cleaning it didn't seem to help. Any other suggestions? The problem has been going on for a few months and I've taken it to a few mechanics (including a VW specialist) but they can't figure it out. There are no lights on the dash to indicate a problem. The only other issue that I have had with the car is with a fuse that has blown twice; I don't know if that is related.

Writen4u (author) on February 08, 2011:


Count the little points on the screw, if there is six points you can buy the bit or screwdriver at any auto shop for around $5. Just ask for a six point security bit. If it's only five points the only place I have been able to find it is online which is why I offer the method of removing them with pliers and replacing them with trim screws. I should have a DIY for fixing the broken maf clip up in a couple days it it ever quits snowing out here.

morgan on February 07, 2011:

thank you. tomorrow i have off work so im going to find a way to get the 5-star or 6 star screws off. it looks like an allen head wrench will fit but it has the indention in the middle so i have no tools that fit it.

Writen4u (author) on February 03, 2011:


If you had no codes before you did this, the first thing that comes to mind would be a throttle body alignment. Did you do one after you plugged the TB back in before you started the car? If not, try clearing the code again, then put your key in the ignition and turn it on without starting your car, if you have the hood open go listen to the TB it will be making a high pitched sound, once it is done you can start the car after that you may have to unplug the battery one more time. (it's all written somewhere in that TB DIY).

Tell me if that solves it.

99jetta on February 03, 2011:

I cleand the maf, and the throttle bo, but then the cel came on, It wasent there before I did this I checked the wires and everything is pluged in, I reset it but it just comes back on. When i start the car the cel fashed once. What could be the problem?

Writen4u (author) on February 01, 2011:


It sounds like he made more mistakes than you would have. I'm not sure what clip your talking about that holds the maf to the airbox, if you mean the hose clip just replace that one with a metal screw type hose clamp. As for the Maf plug clip if it stays secure on the maf I wouldn't worry about it if it's coming off you will need to replace that, it should be part # 4B0-973-724 $30. but check with your local VW parts center. Pretty much the guy broke the only think you needed to worry about breaking so don't worry about taking some screws out. In the future don't let some random person at the auto store tinker with your car, they don't care if they break it because it's not their job and you'll be stuck with the bill. Good luck.

morgan on February 01, 2011:

im not very good at fixing things so im kinda worried about the tamper resistant screws.. when i took my car to o rileys auto shop the guy that helped me unplug the MAF BROKE the clip on the plug.. and broke the clip that holds the MAF housing to the airbox.. he zip tied it shut so its not leaking but now i have to figure out how to go about removing the MAF so that i dont make any mistakes like someone with actual car experience did.

Writen4u (author) on January 31, 2011:


Unplugging the maf is a good way to check if that is the problem and it seems that it is your problem. You don't want to leave it unplugged and ignore it, that could cause further damage to your engine in time. For a few days it's not going to kill your car but I would recommend cleaning it or buying a new maf as soon as you can.

morgan on January 30, 2011:

i have an 01 audi s4 thats throwing multiple codes that point all towards the MAF and the spark plugs. (my system is running too rich with random missfires in the cylinders) when i took my car to an auto shop to get it scanned the guy told me to unplug the Mass Air Flow sensor and to drive around without it to see how it affected it... my question is can i leave it unplugged without hurting anything? it did make a noticeable difference but it made the "ABS" light come on and not to mention the plug is flopping around under the hood scares me. thanks for taking the time to help other people out.

Gobb on December 20, 2010:

Thanks again for another DYI. Did mine yesterday. Pretty painless in most part. Grabbing a hold of the tampered screw was a bit of a challenge. Once you get it going though..it's smooth sailing. Also, i did the alcohol bath since I couldn't tell which part was the actual sensor. I'm planning to service MAF again every time I clean my K&N. Thank U again.

Writen4u (author) on November 11, 2010:


I'm glad I helped and I hope that fixes the problem. These cars can get extremely expensive taking them to the shop for just little problems. The internet is a wealth of info for fixing your car, so save yourself some cash fixing it yourself and don't forget about free car scans at auto part stores to help diagnose problems.


J.Nolan on November 10, 2010:

What a great post! I bought a 1999 Audi A6 which was in limp mode. It is a beautiful flawless auto other than it would only run in third gear. I knew absolutely nothing about Audi's and had no idea of the repair cost! I have had the car just sitting for the last 4 months until this evening when I stumbled onto your blog. What the heck, went outside and unplugged the MAF sensor and behold the car was no longer in limp mode. I am currently cleaning the MAF sensor with alcohol and if it works great if not I will pay $100 to buy a new one. I assumed I was going to have to pay between 1 to 2 thousand dollars to find and fix this problem after reading other blogs. Thanks to your blog and detailed instructions even if I buy the MAF sensor I will have a total of $3,000 invested in one of the most beautiful cars I have ever owned! Needless to say I cannot thank you enough! I am now one very happy Audi owner!

Writen4u (author) on November 07, 2010:


You might want to change spark plugs and clean your throttle body. Usually that helps with a rough idol. Also sometimes a Sea Foam treatment helps. Some people are for it and some are against doing it. I've always done it and have never had a problem, but you will probably want to do your own research.

Writen4u (author) on November 07, 2010:


More than likely that was the problem if you forgot to plug it in. If the light is still on unplug the battery to reset the code. If it comes back then you now there is something else wrong.

Writen4u (author) on November 07, 2010:


Not all mafs have that little resistor on them, yours is located on the intake manifold next to the trottlebody, it's called the IAT sensor. You can clean it by unplugging it, unsrew the 5mm allenhead bolt and pull it out, wash with alcohol.

dale on November 06, 2010:

I like the format here great site..need a little help..cleaned my maf on 95 jetta after that it runs really rough when trying to put in gear shakes and dies,,any ideas. Thanks

kevin on November 06, 2010:

thanks for the diy, i did this myself today and i noticed that i do not have a thermistor where the maf has a little pic of one. on a 2003 gti 20ae 1.8t are they supposed to have a thermistor? thanks

Corrie on November 02, 2010:

I bought the part new from a good source. I have been meaning to replace it for a while and just finally did.

The only thing that I can think of is that when I first replaced it I forgot to plug it in. drove up the street and back and popped my hood, out of habit and that's when I realized I never plunged it in... I am a moron I know.

Could that have something to do with it?

Writen4u (author) on November 02, 2010:


I would try unplugging the maf and making sure it is plugged in all the way also reset the code by taking the negative terminal off the battery for a few seconds. If it still is on it could be a few different problems, one of which could be that your maf is to bad for a cleaning. Your best bet at that point would be to get a free scan at an auto parts store so you can narrow down the broken part instead of wasting money on sensors and a new maf.

Sorry I just noticed you "replaced" your maf sensor. Was it new from a reliable source? It's bad but some people like on ebay just pull a maf out of a junk yard car stating it works when really they have no idea.

It's not a bad thing to drive with the light on, it just means your anti slip regulation is turned off.

Corrie on November 02, 2010:

I just replaced my maf sensor and I was wondering if you knew why my ASR light came on and won't go off? is this a bad thing?

Writen4u (author) on November 01, 2010:

Hi john,

Yes you can clean the screen so none of that dirt and grime get back on the sensor. Next time you pull it out just put the whole housing into a bag of alcohol and give it a good clean by shaking it up.

john n on October 31, 2010:

I have a 2001 1.8 audi tt. I cleaned the MAS. should I also clean the screen mesh that is in the housing. It has a lot of black stuff on it. I put everything back together and the engine runs great again. thanks.

Fahim on October 28, 2010:

Excellent write up! If only there were more people in this world like you, sharing their knowledge on the internet to help others. How very un-selfish of you.

I thank you sir.

Your friend across the pond in London.

Writen4u (author) on October 20, 2010:

No problem.

If I can help I will, but some of these problems I get asked I have no idea of what could be wrong.


Christen on October 19, 2010:

Thanks for the advice! Your the only person who seems to know anything about beetles...

ClutchMD on September 02, 2010:

All I can say is Thank you! I followed the above post and no more low RPM limp mode. Performance increased. You not only resolved my issue but I also learned something. Only have 55k miles on a tuned VW GTI. MAF Sensor will become part of my regular maintenance. Thanks again for the great post.

Writen4u (author) on August 16, 2010:


I don't think you will be able to find the maf at any store. Your best bet would be to buy it from the Audi/VW dealership, they will have them at the parts counter. Besides for that you can always order one online if you trust the source, just make sure it's new or refurbished any part number with an "X" at the end means it's refurbished.

As for the price it fluctuates depending on your engine but a new MAF will be anywhere between 100-200 dollars.

Christen on August 16, 2010:

Hi this is Christen again, I can't seem to find any stores with MAF sensors, do you know of any stores that carry them, and also do you have an estimate of how much it will cost? Thanks so much!

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