Hey, need help to figure this out. Just bought the car and the last guy had put on z1 test & y pipe with isr 3” single exit. The guy said there was an exhaust leak when I questioned him about that sound. When the car was lifted that rattle sounded like it was coming from at the end of the y pipe. Some bit of exhaust leak too, seamed like the clamps there wasn’t doing the job so I had it welded thinking that was the problem. No more exhaust leak from the end of the y pipe to the single pipe but yet it’s still making that noise.

Could it be the test pipe? None of the heat shields seem that loose to be able to rattle into anything but I could be wrong. Asking for your experience if anyone else had this problem.

Videos were not uploading but I just saw on another thread that the rattle and hiss noise that I have is because of the test pipes and is normal. You can delete this post admins