I put a Bassani x-pipe on last week. I got the one that I can run with or without cats. I put it on without cats last weekend. It was LOUD! I don't mind loud but it had the rattle sound that everyone has said you get with the Bassani. Today I put the cats on and it made a huge difference. It is a lot quieter. I would like it a little louder but I did get rid of the rattle sound. It also has the exact tone I was after. I should have listened to everyone the first time. Now I don't have to worry about attracting unwanted attention from smokey.