New DV, new fuel filter, checked for vacuum leaks, intercooler piping is on tight. My car feels like a regular 4 cylinder with about 90 hp. I have tried unhooking the MAF, no change in the way the car behaves. I then unhooked the negative terminal on the battery to clear out any fault codes, the car runs great again! But then the car warms up, and reverts back to crap mode...Could this be a coolant sensor(mine has the green top) problem? I'm grasping at straws here. The goofy thing is, I can't always duplicate these results by unhooking the battery. BTW the car only has 52,000 miles. I love this car, and am addicted to the zippiness! Right now it's like driving a can of caffeine free diet coke, when you know it really should be red bull!