I have a replacement CAT for my Jeep I bought from AutoZone. Problem or issue/non-issue is, the replacement is much smaller than the stock CAT. Inlets and outlets are the same but the body of the CAT itself is smaller. For example: if the stock CAT were hollow, I'd be able to fit the new CAT inside of it.
My questions: Would the size difference cause the computer to start dumping codes at me? Should I try and find the same size replacement CAT? Autozone says it would work, should I trust their counter guys word on that?