i just ordered a high flow cat, made by carsound, and i had the option of either getting it in 2.25 or 2.5. i opted for the 2.25 since my rs*r catback/dc ceramic header was 2.25. now im thinking i should have gone 2.5 for even more flow. what do you guys think?

 

2.25" is fine.

 

there would be no point to 2.5 since the header/exhaust gets small like 2.0 inches so it can connect to the stock cat. unless you were running a 2.5 inch cat back, 2.25 is best.

 

You bought the correct size.

 

cool.. thanks

 

accordcoupe94, so do you feel any gain?
and how does your car sound b4 and after?