There's an emmission warranty on the cats for 8 years. Check that out first to see if your covered.
Linky
First question to ask is, why is my main cat clogged?
Did the pre cats cause this by failing and clog it up?
A $400 repair for the main cat isn't as bad as $2500 for the pre cats.
Linky #2
The consensious on these boards is to gut your pre cats and keep your main cat, as power is lost hollowing out the main cat.
I had gut my main cat, then gut my pre cats, drove around cats less. Recently I have replaced my main cat with a Magnaflow high flow cat.
