This doesnt seem to serious to me, but im just double checking to make sure its fine. I recently put on a 3inch catback. Before i explain i know the evo runs very rich from the factory. Sometimes between shifts, or when the rpms are coming down i hear a somewhat mild back fire/popping sound. Im just wondering is this just the excess fuel burning off the cat, and i just can hear it now because of the 3 inch catback? thanks

 

Perfectly normal. You said it. The popping was there before, but you couldn't hear it. Now, to get flames to come out....