When i get the new cat delete pipe in i will get this install done. I would like to hear how it sounds. Just waiting on parts. It may take a little longer than i anticipated i have been trying to talk myself into going ahead and having the cat delete pipe ceramic coated before i installed it. Don't know about exhaust fumes coming back into passenger compartment. It is one of those deals that you don't won't to do work twice but you hate to keep throwing money at something that may or may work plus time wasted.