No power under full boost, wastegate maybe?
I'm new to forums, but here's my issue. Car runs fine if I don't floor it. When I floor it my boost gauge quickly jumps to 25psi +, but car doesn't go. Then the boost gauge will flutter between 10psi & 25 psi+. In first and second gear car pulls pretty good, maybe not quite as hard as it used too, but pulls decently. In 3rd, 4th & 5th gear I can downshift & not pass a yugo! Lol. No boost leaks in piping (checked numerous times), spark plugs changed, coil packs changed recently and new timing belt. Could it be my wastegate has gone bad? Need a retune? Any other ideas? Got engine read and only codes that show are from o2 sensor (straight pipe), ran fine for 30,000 plus miles with no o2 sensor therefore I don't think that is the issue. Can anyone help that knows subie's in and out? 2005 wrx. Richmond, VA.