Bring car into Mazda due to CEL on and I hear a rattle from underneath at idle. Well, my catalytic converter is broken off on the inside they said. They also wrote this on my service paper. "Inspected and found DTC P0420 Catalytic converter below threshold"... Can I do anything about making the CEL go away without paying anything? Also, what is the cheapest route of fixing the problem if I want the rattle to go away?

 

Gut the cat

Won't get rid of the light, but it will get rid of the rattle

 

The emissions systems and therefor the catalytic converter, is warrentied, by federal law for 8/80,000. They should replace it.
I have had 4 replaced to date.

 

Why do the go out in this car?

 

In my case, I had a bum engine from the time it was new. On my car the would clog up. Since the engine was replaced, I haven't had the problem. It was also suspected the movement from the factory to the boat to the parking spot over here, wasn't long enough to heat it up and unburned fuel was collecting there.

 

I have 99237 miles on the car.

 

Replaced my engine 20K ago.

 

It isn't whichever comes last is it?