Turn up the stereo and enjoy the power! No seriously, I think if you do the up-pipe you should be prepared for the possibility of some noise. It just seems inevitable with this particular piece. I just put the new TurboXS catless up-pipe on my car and I swear it leaks a little when the engine is cold. It's hard to tell because overall the car sounds so different with the TurboXS turboback exhaust and the silencer mod. I can't tell what noise is coming from what. I really notice it when I drive next to one of those concrete street dividers. You hear all of the new noises as they reverberate off the concrete. The noise at higher RPM that you mentioned worries me a bit. I think I have had a similar noise. I thought it might have been a belt slipping. I swear I heard something just before redline. Oh well, don't worry *too* much. It's just a car. All parts are replaceable.