Alrightly folks, my car has a problem. It runs fine at idle. It runs fine at full throttle. When it's at part throttle, whether I'm revving it in neutral, accelerating, or cruising, as soon as it gets above 1,800 revs or so, it starts running crappy. The crappy running is causing the engine to vibrate badly as if it were missing on several cylinders, having severe timing screwups, or running with very bad injectors. This happens hot or cold, just started 10 seconds ago, or running all day, it doesn't matter. I did a voltage check on the O2 sensor, and it read that the car was going very lean (.2-.3 volts) when its running crappy at part throttle. This leads me to believe that not enough fuel is getting into the engine for some reason, either suddenly bad injectors, bad computer, or bad AMM which btw I just replaced 6 weeks ago.

This problem came on suddenly a few days ago. 2 Days before this started, I had accidentally downshifted (M46) at too high a speed and the car was momentarily revved beyond 6,500 revs. Since my car is a B23F (non turbo) it has a hard limiter at 5,800. Of course the speed of the vehicle alone allowed the engine to breech the limiter. I doubt this would cause damage resulting in these symptoms, but am not completely sure. So what do you guys think? Thanks a lot for all of the help.