Hey all i got a BBK off road X-pipe that I had on my 01 GT a while ago but took it off b/c i was making this rattling sound around 3 grand when the rmp's would drop and I have an idea what it is but I am not totally sure about it. I think it has something to do with the back pressure and when the gas hits the X on the pipe. But again I am not totally sure. Now I talked to one of the few that work on my car with me and he said to weld in 2 cats on it and it will take it out. Will that help it? I want to put it back on b/c the HP gains were crazy and it sounded sweet b/c I also have V-force muffs on there. So if anyone can help me out then let me know. Thanks