Hey all, I'm puttin a 2.5" exhaust and extractors in my VL, and was wondering if changing my cat will make much of a difference. The high-flow cat doesn't fit into my budget, but will it hurt to keep my original cat for a little while? Cheers, -David

the cat is just another part of the exhaust system, by law you have to have one, so the less restrictive it is the better your "overall" exhaust will "flow", but having a standard one won't hurt, but a high-flow unit will be better!!!

I noticed a difference but my exhaust was 3" and I replaced the standard cat with a 3" highflow cat

you'll probably be able to measure the difference on a dyno, but prob wont be able to notice much change. especially with a NA. turbo would be different. knock the guts out of your existing one!

Quote: Originally Posted by Jaytee knock the guts out of your existing one! If you do this, weld some pipe in there, otherwise you get a really annoying echo sound. Been there, done that, the gutted cat lasted 2 days before i got sick of it. That was on my old na, my turbo has a 3in cat now Some original photos have not been recovered yet.

from what i noe if u put in a a high flow cat in a 3inch (turbo0 igt just burns out the cat in a week or so ???

Quote: Originally Posted by PISTVL from what i noe if u put in a a high flow cat in a 3inch (turbo0 igt just burns out the cat in a week or so ??? Yeah it does it happened to my old VLT all this flaky black **** was coming out of exhaust!...