I have put brand new engine. (see details). and My catalytic converter is only 1 year old. That's why i think bizarre that the "honey comb" like net on the cat has desintegrated into chunks that i was able to take out with my hands.

I notice this, because iu hear a ratling on the cat.

ANy particular reason why a cat will go this bad???

 

1 year old, huh? That makes no sense. Have you ever bottomed it out on anything?

 

By running rich the gas enters the cat and will destroy the interior of it.