-Why is with two cars now after I put in headers I have **** a high flow cat converter very soon after? They were two different brands also, but both "hi-flow".

 

Thats odd. I've heard of people having them **** out on them, but they called up the manufacturer and they replaced it free of charge since it was so soon after install. Might want to give it a try. Do you have your AIR removed?

 

no, my air and egr are still installed, will be moving to Cali soon.

 

how rich are you running?

 

rich can kill a cat
too cold temps can kill a cat
lean will SLAG a cat (faster than rich).

So make sure your tune is up an up. Hell the stock cat's aren't too long lasting.

Might just run cat-less with a race-pipe except for the inspection period mate they'll last longer heh.