Steve, I to have lagged. I have'nt repalced the Back Pressure Sensor yet. I talked to the powerstroke mechanic and he said since no code was showing up, that he would like to look at the truck first. Here's something interesting though: I woke up one morning to dead batteries. My glove compartment did'nt close all the way thus causing my light to stay on and drained my batteries. I replaced both of them and my truck ran great with no lag. That lasted about a week and the lag returned. I am determined to get this fixed and will keep you updated. If you have any suggestions give me a call.