The current programming is factory. I messed up years ago with the Predator, and had to have the dealership reflash the ECM. Since then I've not needed
More Power Today, 09:44Mine has always done that. Before and after injector replacements (mine's had 2, as well as a separate return line replacement after filling the crankcase
DmaxMaverick Yesterday, 13:37
Both images here are with the transmission in "D" at idle, engine at operating temp.
As an addition...
Duramax Head Gasket Replacement
Normally, I would say no, not necessarily high/low because of indicated high/low cylinders. In my experience, it is not, as long as the PWM's track closer
DmaxMaverick Today, 13:55