When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Lose the cats, but don't just have them cut off. Buy an off road X or H mid-pipe and some MIL eliminators. It will flow better and you can always return it back to stock.
To answer your question, you'll pick up both power and torque. I had a notable improvment at the track with the O/R/X. Not sure exactly how many horses/torque were gained.
if you need to pass emissions you can get some high flow cats which will help w/ power over stock cats too
Or you could jus buy and o/r mid-pipe, keep the stocker and slap it back on real quick the day before you go get your emissions test, then slap the o/r pipe back on! Quick 30 min. process to swap them!
just remember when u run with no cats ur gonna need either a tuner to delete the rear 02's or MIL eliminators (which i bought and they didnt work [:@])