will a high flow cat fit fine on a stock GSR exhaust and Header? or do u recommend getting all new stuff?

 

i dnt think there really is a point to getting a high flow cat with stock exhaust and header....u are increasing flow in the cat which might give u 1 HP but if u dnt get a new exhaust and header it would be pointless.

 

what if i were to buy ITR exhaust and cat and headers? will that work?

 

anyone?