The Catted X-pipes will pass smog and the NON-catted will not. You will get a much deeper and louder sound out of a non-catted X-pipe,But they are illeagle on poluition controlled cars.
They will give a couple of extra HP over the catted version. If you have to go for smog checks and dont work on car much get the Catted , otherwise get the Off Road version. LOL
I am not a Psycho
I just play one on a PC!
Sold to a good home(4/13/2010) - 2000 Stg 2 KB'ed Vert
2001 Expid-Harley conversion
05 - 350Z vert
07 - IS250
Yes....I think I am turing Japanese...at least I drive so ?