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Catalytic converter burnout

I have a 2002 Chevy Impala which I love. It has burned out 3 catalytic converters in the past year. They were replaced under warranty, but the mechanics think there is any underlying problem. Ever heard of this before?

Your mechanic is right, the burned out catalytic converter is a symptom of something wrong in the engine.
You need a mechanic,while the car is still under the warranty coverage, to find, and repair, the cause of the burned out catalytic converters. You might consider another dealer to do warranty repairs. For non-warranty repairs, go to an independent shop.
It might take the zone rep to put a bee in the bonnet of the dealer to repair the car correctly.

Any Check Engine Light on? Any codes present? How many miles on the car?

If the converters are all legitimately bad and this is not a misdiagnosis the converters could have been ruined by coolant entering the exhaust (intake, head gasket leak, etc.) or by running excessively rich (very poor engine performance due to chronic engine ignition misses, leaking fuel pressure regulator, etc.).

If the mechanics suspect an underlying problem then what have they done to find ths problem?

Thanks for the info. I bought the car new in 2002. It has 102,000 miles on it. When we replaced the first CC we also had to replace the oxygen sensor. No other codes were seen, no coolant leaks. Was just looking to see if anyone else had run into this problem and what the outcome was.

There’s only two things that can burn out a catalytic converter. Either too much fuel all at one time causing thermal shock, or too much fuel over an extended period of time causing overheating. Look for a problem in the fuel system.


I will only add one thing. Assuming it is under warranty, make sure you document everything and you may want to check out your states lemon law.