Dan Ferrell writes about DIY car maintenance and repair. He has certifications in Automation and Control Technology and Technical Writing.
Oxygen Sensor Replacement
If you know how to change an oxygen sensor on your 2000 Dodge Stratus, you not only save money on the repair but also avoid a much more expensive repair that could happen in the future if you ignore the problem. The trick is in both removing and installing the sensor. After years of service, an oxygen (O2) sensor tends to firmly stick to the exhaust pipe or manifold due to the high temperatures under which it operates, making it difficult to remove and increasing its potential to cause damage. Then, you need to follow the manufacturer's torque suggestions to prevent damage and exhaust leaks as well. Putting off the repair for a long period of time is not a viable solution.
The oxygen (O2) sensor on your Dodge Stratus helps the computer determine the right air/fuel ratio for better engine performance and emissions control. Once the sensor fails, your gas consumption may go as high as 25 percent, increasing emissions and decreasing engine performance. This will trigger a Diagnostic Trouble Code (DTC) and the "Check Engine" light, which won't allow your engine to pass the emission inspection.
Common Symptoms of a Bad Oxygen Sensor
- Engine hesitation
- Poor engine performance
- Poor gas mileage
- Black exhaust smoke
If you want to replace an oxygen sensor because of a trouble code stored in your computer memory, make sure the sensor is actually at fault. Many sensors fail to produce the correct signal due to a loose or corroded electrical connector; other times, a problem in a related system — for example, a disconnected vacuum hose — may cause the O2 sensor to produce the wrong voltage, making the computer believe there's something wrong with one of the O2 sensors or its circuit.
Once you've determined that you actually need to replace one or more oxygen sensors, follow this guide to replace them without fear of causing physical damage to the system, and with the confidence that you're doing the repair right the first time.
But first, let's see what tools you'll need to gather for your repair.
Tools for This Repair Job:
- Floor jack, if necessary
- 2 jack stands, if necessary
- 2 wooden blocks, if necessary
- Oxygen sensor crow’s foot wrench or oxygen sensor socket
- Short ratchet extension
- 18mm x 1.5 + 6E tap, if necessary
- Electrically conductive anti-seize compound
- Torque wrench
Make sure you have all the necessary tools and items on hand before you start to make your repair easier.
How to Change the Oxygen Sensor
Before you actually remove the sensor, it's a good idea to ready the old sensor(s) to make it easier to remove and reduce the chance of damaging the boss's threads on the exhaust system — where the O2 sensor mounts.
* First, you have the option of taking your Stratus to the highway for a 20-minute drive (this will raise the exhaust system temperature and help you loosen the sensor). Then, head back to your garage and loosen the sensor. Next, let the engine and exhaust system cool down for about an hour or more to prevent serious skin burns during your repair.
* Alternatively, the night before you plan to replace the sensor, soak the O2's base (where it threads onto the exhaust pipe or manifold) with a quality penetrating oil. Spray more penetrating oil about an hour before removing the sensor — read the instructions on the product's package for best results.
Choose a level surface to park your car for the repair, if you need to raise the vehicle to replace the sensor. When ready, open the hood and disconnect the negative (black) battery cable from the left strut tower — driver's side — using the wrench.
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Now, locate the sensor you want to replace. You'll find the upstream O2 sensor right on the exhaust manifold and the downstream O2 sensor near the catalytic converter. To find the downstream sensor, follow the front exhaust pipe that connects to the exhaust manifold down towards the catalytic converter. The sensor itself has the size of a spark plug and has three electrical wires coming out of the sensor's back end.
Jack up your Stratus if you need better access to the oxygen sensor and set your vehicle on jack stands. Block the rear wheels with two wooden blocks and apply the parking brakes.
If you need to crawl under your car to reach the bad sensor, put on your goggles, and then unplug the oxygen sensor electrical connector. Follow the wires from the back end of the sensor and detach the wires from the clips that secure them to the vehicle’s body.
Unfasten and remove the sensor from the exhaust manifold or pipe using an oxygen sensor crow’s foot wrench or oxygen sensor socket, a short ratchet extension and ratchet. The special sensor socket fits over the sensor and comes with a cutout to accommodate the sensor's wires during removal and installation. A crow's foot wrench seems more practical to use if you have enough room to work around the sensor.
After removing the sensor, clean the mounting threads of the exhaust boss with an 18mm x 1.5 + 6E tap — this will help you apply a true torque during the installation.
Check the threads on the new oxygen sensor and make sure they are coated with an anti-seize compound. If not, apply a light coat of this compound. Some manufacturers include a small plastic bag with this compound in the sensor's box. You need the electrically conductive type with liquid graphite and glass beads to prevent electrically insulating the sensor. The compound prevents the sensor from "welding" to the exhaust pipe or manifold, so you'll have an easier time replacing it next time.
Start the new sensor by hand into the boss and then tighten the sensor to 20 ft-lbs. (28 Nm) using the torque wrench and the crow’s foot wrench or socket. Torque-guessing while installing the sensor leads to a bad installation and repair: Over-tightening the sensor will damage the sensor itself and the boss threads; under-tightening it will cause exhaust leaks.
Plug in the new oxygen sensor’s electrical connector. If you are replacing the downstream sensor, secure the sensor's electrical wires to the clips on the vehicle’s body as well. If you are replacing the upstream sensor, make sure the wires are securely away from hot surfaces and moving parts.
Finally, double-check your repair if necessary. Remove any tools from under the vehicle. Lower your Stratus off the jack stands and connect the battery's negative cable to the strut tower.
Take Good Care of Your Car
Knowing how to change an oxygen sensor on a 2000 Dodge Stratus is not difficult, and neither is damaging a component or doing a bad repair. So keep this guide handy. When the time comes, follow these same steps to replace the other O2 sensor. You'll save over a hundred dollars in labor costs. Check your manufacturer specifications — found in your vehicle repair manual — and replace your oxygen sensors at the recommended schedule. You'll avoid surprises while on the road, save on gas, and help your engine operate efficiently. If you need some visual help about how to remove an oxygen sensor or the tools needed to remove the sensor, check the video below.
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.