I've got a rattle that's coming from my left exhaust pipe. It started when I put on the x-pipe and 2 chambers so can't really go to dealer on this problem. I have taken it to a muffler shop and they're are pretty sure that it is coming from the tail pipe. Supposedly since our pipes are different and have walls....my problem is that the walls are vibrating and touching??!!!?!?!? Beats me how that occured. He said to fix the problem, I(or he) might have to weld the rear hole(where water drains) on the pipes. I wasn't too sure about that so I am just living with the rattle for now. Should I have welded the hole or not? I mean it is there for a reason so why weld it shut. Appreciate any feedback.Thanks.