From what I've been told, on the 2001+ exhaust systems on any truck we're built with high flow cats, even if there is 4 of them. I had 4.. 2 pre cats and 2 post cats (pre cats coming off each side of the manifold, and 2 post cats after the y-pipe). I just recently finished a rear cat delete so now I have 2 pre cats and 1 post cat. If you can find an exhaust shop to bend you that bend, and have a buddy WELD it up (Not solder, that's for electronics, sorry) you can run 1 cat less. I've noticed a throttle response increase and sound as well as some mpg even with 35's.
But since you're in california, you may have to find special cat's... All that emmisions ****. Blah.
FXEdgeplorer Level II
Part 01, 02, 03, and 06
Tall, Slow, Shiny, Loud
6 Lug Ranger
D44 SAS'd on 12" of lift and 37's...