The fact you hit the gas and OP increases is a clue the system is working (how accurately is anyone's guess). I know several folks have had a CEL come on after various mods but TMK never a low OP reading. These CELs have generally gone off after a day or two. You may have triggered the light but certainly did not cause low OP. I would have it checked and be very careful on the sequence of events as to how this happened, DC is just itching to void warranties. I am not suggesting you lie but no point in giving a lot of info they don't need, your low OP needs to be addressed. They should check with an external OP guage to see if it is low, I imagine a device like this exists and I am sure they have never heard of one. Gluck.