catalitic converter problem

[CoryM]

The two most common causes of failed catalytic converters are:
-engine burning oil. This causes too much fuel for the catalyst to react with, and it melts.
-vibration. Such as a broken exhaust support bracket, or even just a rattling heatshield.

It is also very common for inexpensive aftermarket cats to only last a year or two; Even in good conditions. They use the bare minimum of the expensive catalyst materials to meet OBDII requirements (and sometimes not even that).

Yes, over-fuelling can cause cats to fail (same reason as the oil), but newer cars are much less likely to over-fuel that much without throwing a code.

Do you notice any blue smoke from the tailpipe when starting it cold? Any buzzing or rattling noises from the exhaust?