I added a resonated test pipe with the electrical SES fix and subsequently threw an SES and the car has a stumble during steady throttle @ 3/3500 rpm. The car will sputter and not make much boost when you accelerate. If I engage the clutch, give a quick rev, when I release it drives as usual for a bit. Under full throttle it seems fine. I haven't had a chance to pull the code yet. Any one have an issue like this? I have an Xede, CB, KN drop-in, and didn't have this problem on my '03.