Had a rattly left pipe. Finally got the better of me. Drilled out the end cap but now faced with a much bigger job. NowI can see why the stock pipesare so restricted. Hate to think how many chambers there are.If I'm going to tear the entire pipe to bits to find the rattle is there a mod that I should do while I'm there. Obviously I would need to do it to both sides. I know it's not as good as a new system but it's all I have access to at the moment.