How to Replace a CAT Converter


1. Use a jack to raise the car up. Place two jacks on the front and two on the back. Ensure the car is stabilized by using jack stands with the jack support points.
2. Lubricate both the bolts and clamps so they will be easier to remove. Loosen the bolts with an adjustable wrench, since bolt sizes vary. Remove the bolts and put them somewhere safe.
3. Remove the heat shield and clamps. Shake the catalytic converter slightly and pull it from the pipes. In some occurrences, you may need to use a rubber mallet and tap on the converter to release it.
4. Check the connecting pipes for damage. If you see damage, you might need to replace the pipes, while a small crack or puncture can be replaced with an exhaust patch kit you can purchase at an automotive store.
5. Attach the new converter to the exhaust pipe that comes from the front of the vehicle. You may need to use the rubber mallet to ensure that the converter is securely fastened. Align the exhaust pipe from the vehicle's rear with the catalytic converter's back hole. It may require pushing the pipe back to get it fixed. When it is properly aligned, push the pipe one inch into the converter.
6. Put the heat plate back on, if you removed one, then replace and secure the bolts. Come out from under the car then start the engine. See if the new converter is leaking. Most leaks occur where the exhaust pipes meet the converter. Should you see a leak, you will need to use the automotive exhaust patch kit to patch it up.
7. Remove the jack stands and lower the vehicle. Write the date of the replacement in your auto maintenance manual. Some states, like California, require this information with auto inspections.
8. Check to see your state's requirements for disposing of catalytic converters. Some states require you to take it to an approved location for disposal. You can find this by contacting a local auto store or mechanic.