Originally Posted by westcoaststyle

I do believe that the JDM 4-1 header will have a 2.5" collector so you won't find an OEM cat with that size flange on it. You will either need aftermarket or the JDM cat.

Either way, you will have to have the exhaust lengthened to meet up with the cat or have a spacer pipe made to fit the difference.

hih doood