To make long story short, I am driving an 06 a4 2.0t. manual. I am running apr stage 2+(magnaflow catback, test pipe, high pressure fuel pump, carbonio air intake).
I was doing about 55 mph in 5th gear when I decided to pass a semi truck that was in front of me. So I shifted down to forth, got into the left lane, pushed the gas and........there was no torgue at all. I was like " Damn it, am I so clumsy that I put it in 6th instead of 4th?". But no, I was in 4th, I was in the right gear, there were no signs of torgue though. I stopped at a red light a mile after that, when I started taking off it wasn't any better. First I thought that the clutch was spinning. I doubted it because I just got brand new clutch 1000 miles ago but it just felt lack there was no power. That car was slower than a stock a4 at that moment. Then I thought that the turbo went bad as I couldn't hear it, nor feel it. I was scared to hell. Turbo is the last thing that I want to spend money on right now. So I pulled the car to the side of the road, turned the engine off, pulled the key out, let it sit for at least 2 minutes, started it again and it was fine, it was back no normal. So I am assuming that the computer had to be reset. I am not sure if that is what it really was and why it happened but it was pretty interesting experience.