Hi, Please could someone help me, i have been really struggling with this. My ecm is a E38 with 6.0L L98 motor, the car is an 08 Lumina SS. My LC1 WB in closed loop MAF reads on average 14.20 AFR, but my command AFR is 14.63. I have tried to adjust the switching point, and after every attempt i have reset fuel trims. Why does it not want to change. Am I doing something wrong. Mark