Surges Or CHUGGLES

Check ignition system and grounds.
Check PCM and ignition grounds.
Check for contaminated fuel.
Check for restricted fuel filter.
Check fuel pressure.
Check for injector leakage and connections.
Check for intermittent EGR at idle.
Check for incorrect charging system voltage.
Check for faulty PCV operation.
Check for faulty throttle position sensor.
Check oxygen sensor for silicone contamination from fuel or improper RTV sealant.
Check for faulty MAP sensor.
Check for faulty coolant temperature sensor.
Use scan tester to ensure vehicle speed sensor reading matches actual vehicle speed.
Check for faulty A/C operation.
Check for faulty park/neutral switch.
Check MAF sensor connections.
Check vacuum line condition and connections.
Check generator output voltage.
Check restricted exhaust system.
Check O2 sensor.