ok so im trying to help a friend get his Silverado sand rail going. It has a 6.2l escalade motor swap with ecu and a 4l80 that is full manual no electronics. Now the motor starts right up and stays running. and will rev up when you hit the throttle in park. But as soon as you put it in drive its like it has no throttle response and has no power. After looking at his tune it says that vats is still enabled, could this be his problem? it has no dtc present.