Negative fuel trims mean it's rich sir.
But the computer is reading lean conditions correct? Could it be that the high boost is causing the stft's to influence the overall ltft's to be that negative all the time? Its usually around -11% and I tend to drive the car pretty hard. I don't have a wideband hooked up yet to see if the computer is getting an incorrect signal from a bad o2 sensor or something like that.
