Ok, I am tuning my buddies 07 Cobalt SS with a 2.8, CAI and 42# injectors. We dyno tuned it and got 12.0 across the board, car runs great EXCEPT that at 5800 RPM on EVERY pull, the car dumps about 10% more fuel and pulls 3* of timing for 100rpm range. As a result for about 200rpm the car loses 15hp. I can post dyno sheets and scans when I get home. I turned off all the torque management and boost knock-off because it was pulling boost at that point before. Looking for ideas.
Ben