Ive heard alot about the high flow cats like the RT and the carsound, ive searched and ive seen people saying they are great, help emissions etc, but combined with a Y-pipe does it make that much difference? Im ordering the WSP Y this week and i dont know if i should get just the pipe or the pipe with the cat for $100 more. Any help is great!

 

Max gain is about .5hp. If you already have everything else for your car, then it's worth it. If you don't, save the money for something else...
-Cyrus

 

Right now i have a stock exhaust, i have about 500 bucks to play with so i figured at least 225 on the ypipe unless i get the cat too, but if it doesnt make that much of a difference ill just get the pipe and maybe the fstb.
Thanks