Re:2007 avalanche 5.3 flex fuel

Already looked it never would go into open loop. Always stayed in open loop fault. Also used functional test to put it in open loop still horrible lack of power.

Plus after that I unplugged both upstream then wot it still garbage. Then unplugged maf still no power. I’m going to redo the injector balance test cold see if they come close to what Ben said around 23 psi for the drop pressure. Tested fuel quality and pressure. Exhaust back pressure. Next want to check cam crank relationship and map sensor because of the strange reading at idle of 2.5 volts

Plus o2 sensors are being replaced per customer request for heater codes.

I got it hot and wot it in park and also power brakes it. 3 psi

@ Tyler it’s the vin 3 lc9 engine