Q: Should I replace or clean the catalytic converter?

asked by on

I was told I have a bad catalytic converter my car is not displaying any of the symptoms of bad converters but the engine check light is on so should I try a cat cleaner first?

My car has 165000 miles.
My car has an automatic transmission.

Hey there. The Check Engine Light can set if the catalyst efficiency is below threshold. There will be no visible symptoms at all, or change in engine performance, because the recorded "low efficiency" can simply mean that more pollutants are being emitted in the exhaust rather than destroyed or "converted" in the catalyst.

So to perceive a difference you would need a gas analyzer to measure what is going on with the tailpipe emissions. Before trying a catalytic cleaner (which itself is problematic if you have a particular product in mind, ask the manufacturer if they have any written, independent laboratory test evidence that it actually works. If they have nothing in hand to send to you, don’t waste your money), the pre- and post-O2 sensors have to be tested in order to determine whether the catalyst has really failed. There is a specific test strategy using output from those two sensors that has to be employed; an exhaust gas analysis is useful as well. If you need help having this checked, a certified professional from YourMechanic can come to your car’s location to diagnose the car and can replace the catalytic converter if necessary.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Should I replace or clean the catalytic converter?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Replacing timing belt on a 2001 Ford Escape

Yes it is and you should change it right away, because mileage is mileage and time is time. That baby is 15 years old. They tell you that you are supposed to change the belts and they are only good...

Q: Engine over heats no heat

If you do not have any circulation through the radiator then you may have a clogged radiator cores inside. If you used stop leak in the engine then you may have plugged up the radiator and heater core. You should...

Q: P0420 P0430 trouble codes

Hello. Thanks for writing in. The universal oxygen sensors, a bad connection, or a bad catalytic converter can all be the cause of the codes. If you can you access to a known good oxygen sensor and test it in...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.