i have a 2 inch header and a 2.36 exhaust and i need a cat. i was going to order one for 160 that was 2 inch in and 2.25 out. The guy told me that the 2.25 would connect to a 2.36. once i heard that i thought maybe the 2 inch header will hook up to a 2.25 cat as well and it would save me a lot of money becuase i could get a regular 2.25 in and out cat for 70. If you know the answer to this question let me know.