I just finished putting a 427 LS7 into a 2000 C5. I did a MAF tune on the car and it holds 14.7 at idle and at cruse. I decided to do a Speed Density tune on the car to dial in the MAF tune a little better.
When I go into Open Loop the AFR jumps between 17-18 non PE, this also happens when in gear. When I have the MAF on it will hold the correct AFR 14.7
I'm at a loss for where to look to correct this, I know its something simple and I ruled out any air leaks.
Thanks