I'm not sure how well they inspect your cat when the they do the inspection but if they just need to see it for you to be legal you can do something I did. I took the cat off, cut open the top side and gutted the honeycomb inside, then welded it back up and put it back on, so when you looked under the ride it looked like a completely normal cat but essentially it was just a slightly larger piece of hollow exhaust tube. And I have a flowmaster 40, love the sound, not loud at all but you know it not's stock when you hear it.