I have an h pipe with two cats on it. I was wondering if gutting them would be worth anything? Will it make it louder and perform better? I have flowmaster mufflers already. What do you think will happen if i gut them?
It would do nothing for you. If anything the extra turbulence would hurt performance. There also won't be any real gains in power from going to an off-road version. Maybe a little sound difference and smelly exhaust. The money would probably be spent better elsewhere, unless the slight sound increase is a must have, IMO.
If the h-pipe already has hi-flo cats you won't get much of a gain in sound. if they are original cats then you will get a noticeable gain in sound but probably not much performance. I would opt for leaving them be or getting hi-flo cats unless you know someone who is going to get you stickers for your car. i had no cats when i went to get my car inspected and they wouldn't even go near it. it quite a fine for them. i ended up having to get the hi-flo cats anyway and now i am legal.