Skip to main content

How to Fix the Exhaust Pipe or Muffler

Dan Ferrell writes about DIY car maintenance and repair. He has certifications in Automation and Control Technology and Technical Writing.

You can fix an exhaust pipe or muffler at home following this guide.

You can fix an exhaust pipe or muffler at home following this guide.

A DIY Guide

You can learn how to fix the exhaust pipe in your vehicle without having much mechanical experience. The average car owner can make the repair at home, depending on the size of the damaged area and access to it. Over time, water and acid content in exhaust gases combine to eat system components, leading to rusted, broken or leaking pipes and mufflers.

Often, you don't have to replace a whole pipe or muffler. Still, you need to fix the problem as soon as possible to prevent it from spreading and keep poisonous exhaust gases from entering the passenger area of your vehicle.

With a few tools and the proper safety precautions, you can save a lot of money by patching, joining, or replacing a section of a damaged exhaust pipe or muffler right at home.

Making a Visual Inspection

First, you need to assess the damage to the pipe or muffler. Closely examine the area around the exhaust pipe you need to fix.

  • When dealing with cracks or holes, you have several repair options. Products like exhaust repair paste (putty), cement crack, muffler concrete, and other similar exhaust repair kits are readily available in most auto parts stores. Some of these products, sometimes used with a rust converter (to prevent rust from spreading on a surface) make for a quick, practical and lasting solution for most damaged pipe issues you will have to deal with.
  • To replace a section of the exhaust pipe, however, you have other alternatives. First, using a vernier caliper, measure the length and diameter of the damaged area on the pipe you want to repair.

You might be able to cut off that damaged section and replace it with a small piece of pipe using exhaust adapters or spacer pipes. Ask for the available diameters at your local auto parts stores. Even if you can’t find the correct diameter for your needs, consider using an exhaust pipe expander tool to adjust your pipe to an available diameter. If you need this tool, your local auto parts store may loan it to you.

To fix a bent pipe, your local auto parts store may lend you a pipe shaper tool to restore the pipe to its original shape. Also, make sure you have the necessary installation hardware like muffler clamps and/or U-bolts.

When replacing parts, keep your system configuration within state and federal regulations. For example, don't remove the catalytic converter without installing a new one.

Scroll to Continue

Read More from AxleAddict

Repairing Your Exhaust Pipe or Muffler

You can find different exhaust repair kits available (especially patches and tapes) at your local auto parts store. Always follow closely the manufacturer's instructions on the product’s package.

A common repair involves:

  • Cleaning, wire brushing, and sanding the area you need to fix.
  • Warming up the exhaust system by idling the engine for a few minutes.
  • Placing a piece of aluminum (cut from a soda can) over the hole or crack you need to repair (unless you're using putty, you may use a metal screen), being careful not to burn your hands in the process.
  • Using a patch or wrapping a tape around the damaged area of the muffler or pipe.
  • And securing the tape with a clamp or wire.

As you operate the vehicle, the heat in the exhaust will melt the patch or tape and seal over the patched area after a few miles of driving.

Common tools for cutting exhaust system parts

Chisel cutter

Chain-type tubing cutter


Exhaust pipe cutter

Replacing a Pipe Section

For a more involved type of repair like installing a pipe extension to replace a rusted or broken piece of pipe, you will need to make some preparations:

  1. Park your car in a well-ventilated area.
  2. Raise your vehicle and set it on jack stands or wheel ramps. Set the emergency brakes and block the wheels on the ground to prevent the vehicle from rolling.
  3. Block the front or rear wheels with wooden blocks to prevent the car from rolling while you work underneath.
  4. Now, put on your safety glasses and crawl under the car.
  5. If you have to remove any screws from the exhaust system, you may need to apply rust penetrant to the bolts to make them easier to turn; only use six-point sockets or wrenches to prevent rounding off the bolts.
  6. Go ahead and cut off the piece of exhaust pipe you need to replace. Choose the best tool for the job. Cut the pipe with a hacksaw, exhaust pipe cutter or chain-type tubing cutter. Your auto parts store may let you use the appropriate tool for the job. Of course, you can make your job easier using an electric saw, but you'll be producing a lot of sparks, and that might not be as safe as using a hand tool, especially when working close to the fuel tank.
  7. You'll probably need to install an extension pipe to join the two ends again. Choose the appropriate size at your auto parts store. If you need only a small section, you may need to cut the one you get from the store.
  8. Use an expander tool to flare out one end of the pipe you need to join so that it is round and uniform.
  9. Measure how much of the expansion pipe you'll need to join with the other end of the pipe. Take into account the overlap of the expansion pipe onto the end of the other pipe.
  10. Raise one end of the pipe so that it is at the same height as the other end you need to join.
  11. Use a floor jack to raise and hold the pipe in place, if necessary
  12. Cut the extension pipe to the correct size.
  13. Widen the extension pipe with the expander tool so that it slides over the other piece of exhaust pipe.
  14. Secure the extension pipe at both ends to the old pipes using exhaust clamps. Don't over-tighten the clamp bolts or you'll end up with an exhaust leak and more repairs to deal with.

You can also use ready-to-install pipe adapters if you find the correct diameters for your application. Watch the next video to see how you can install them.

Save Time and Money

Learning how to fix the exhaust pipe or muffler—including broken pipes or small leaks—is not as difficult as you might think. A close visual inspection of the damaged area and a visit to your auto parts store to check available solutions will help you perform this repair job at home in most cases. This relatively simple fix can solve your exhaust leak, pollution, and noise. So taking care of the problem on time not only saves you money in car repairs but also stops toxic gases from reaching you and anyone else riding with you.

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.

Related Articles