Originally posted by clickwir
does it help to get a new cat if going for a new cat back system too?
well lets say you have 2.5 or 3 inch piping with a regular cat then the air is not going to flow as much if you get a new pipe with bigger dimension. Then of course that won't matter unless you get headers, and intake.
Originally posted by clickwir
does a cat get "build up" over time and use?
what?