Ok so i recently switched exhausts from a corksport system which was 2.5 to a magnaflow which is 2.25. Now i got one cat on it though, which will be off by next week. I got a feeling it will sound like a nice civic after that cat is off...i don't want that. So i might switch back to the corksport. I was wondering how many people here have 2.25 exhaust with a header and are there any dynos to see if there is a difference in 2.5 and 2.25 or are the gains the same while the power band changed? After switching to this system i can say my throttle response is right there, my accelerator seems more sensitive, i got a lot of torque down low and i feel like this was the biggest HP gain. I searched the forum regarding this and i didn't find much. I found most people going with 2.5 because it "seems better".