ok i have a 5th gen civic coupe and i just recently bought a thermal cat back. right now i have a gsr motor in there w/ a gsr cat and a greddy cat back that was modded by the muffler shop.

i was planning on buying a resonated test pipe for a gsr but i dont want to cut up a brand new exhaust to make it fit,is there a cat like the ls or r that will fill the gap? or is custom the only way to go?

just by chance would anybody know if the gsr cat will bolt to the cat back? same size bolt pattern? (the 3 holes)

and would anyone know the lenght of the gsr cat?

thanks for any help...

 

use a 99 si header and your stock civic cat.