Surely you all know the history of my car by now.. only boosts to 5.5psi then slowly goes down.. it seems that one or the other of the cats are clogged. I'm guessing it's the main cat. Took it to a muffler shop, told him "I think the precat is fried and broke up, throwing itself into the main cat and clogging it up". He said he could fix it with a straight pipe for $30 (good deal in my opinion, pretty cheap

Anyhow, assuming the precat is TOAST, and the main cat is no longer existant, how much boost should I be expecting now after the main cat is gone (and no longer clogged I guess).

 

It depends on the diameter of the pipe but with a 3" one(which is what you should get) and everything else stock, I'd say you should see... about 8 psi when it's cold.

-Colby

 

I have no cats, a 3" cat-back and a pod filter, and see 8psi.

 

I have 2.5" DP, gutted main cat, 3"TID, and cone filter and I see 8 sometimes 9 PSI.

 

sweet.. I was thinking that I would be closer to like 10.. good thing I'm not cause I just want it to RUN.. not run super super fast.. I don't have the $$ to upgrade the fuel yet.