I have a 93 300 CE Cab with a low end hesitation with popping through the intake, even in neutral at idle. Recent work done was headgasket and wiring harness. The car ran fine after this project. Started car with low battery and that is when the problem developed. Since reading the codes replaced or swapped MAS, throttle actuator, OVP, O2 Sensor, and fuel pump relay to no avail. At higher rev's seems to clear up some but comes right back. Any ideas?

TIA
Dan