[RobsgottaM3]

I installed a set of PLM downpipes about 2 weeks ago and I think I have an exhaust leak but I am not 100% sure. It sounds like a rattle/hiss. Its only noticeable on startup when the engine is cold and under acceleration. If you have the windows up you can't hear it at all. If you rev the engine while in park or neutral you can't hear anything. I have replaced the gaskets from the DP to the mid-pipes but the sound didn’t change. Could it be the waste gates or turbo? I know it's hard to diagnose without hearing the actual sound but I wanted to see if anyone else ran into this problem. The car seems to be running fine until I get high in the RPM's then it seems to shudder. I haven’t had a chance to run any logs yet. I have also changed the settings on my JB4 with no change to the waste gates. Any help would be greatly appreciated.

Rob