Originally Posted by pinky_and_me
Most likely the ECU was reset so it has to relearn everything.
This gets thrown around too much. The ECU does not have to 'relearn' enough to make enough of a difference to feel it. The only thing it makes permanent adjustments to are the PID files for the WGDC control. Its not like its changing timing advance or vanos angles or anything. I could be totally out in left field here, but I just don't see it.