My check engine light went on and it was diagnosed with catalytic converter failure. I was told that this will be covered under the 8 year 80,000 mile warranty. Then they said that it failed because of something wrong with then engine. I have yet to have them check this out and figure out the engine problem, but is it possible that there is an engine problem a result of the cat. Converter failure? If so, shouldn't the engine repair be covered under the cat. Converter warranty since the cause was the converter failure to begin with?
If the cat failed due to an engine problem it was probabaly a bad oxygen sensor. The warranty generally covers cats that rust out internally and fall in on themselves. You can whack it with a rubber mallet or your hand and see if it sounds like there is loose material in it. Then the warranty should cover it.