Hi guys I bought an RS-R EXMAG full catback for my swapped EK hatch.

I have a B18C (jdm GSR) to put in but I dont know which cat to use?
I was going to go for a universal catback by magnaflow but then i didnt know which one to get or what size?

I tried looking, i think i need the one with two O2 sensor bosses. But its only 2" diameter?

The RSR is 2.5" inlet diameter, anyone have any recommendations?
Would it be easiest to install with a 2.5" cat or something smaller like 2.25"?

Sorry if this is a newbie question,
Thanks for the help!

PAT

 

Anyone?

Maybe ill rephrase, is it easier to put a 2.25" cat or a 2.5" one on a 2.5" inlet diameter exhaust?

 

it wont matter what size the pipeing is. its all about the flange.. but if you go witha smnaller pipeing on then your exhuast wont flow as well as if you had one that all matched..