2002 with L61 engine with 5 speed. I have been ripping my hair out with this thing. It keeps throwing the map sensor code and occasionally will throw a P0171 code.
I verified manifold vacuum is good. Fuel pressure is rock solid even when it starts surging. O2 voltages drop below 100mv's at times which kind of backs up the 171 code.
Verified no vacuum leaks. I have replaced MAP sensor with new GM part and it made no difference.
I am kind of at a loss with this. Has anyone had any similar issues with their Ecotec?