I was talking to a friend yesterday and i said i wanted to leave my CAT on when i get my Cat-Back , he said if i leave on tha cat, there wont be much of a differnce from stock power???
Is tat true??

 

Yep did the same thing had it on, and decided to take it off and i could tell a much better power gain.

 

If you still want to stay emissions legal... yank that nasty pre-cat and stock cat out, get new pipnig from the exaust manifold back... and get like a bonez high flow cat. That won't get you as much HP gain as having no cat.. but will definately be better than a 15+ year old clogged up cat.

 

yeah the restriction is in the cats not the cat back