Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
several codes p0642 ref a 5v p2110+p2118 boththrottle body related mil on etc+esp on .after printing ecm/engine perf. diagram i ckd all related circuits and sensors found no chafed or exposed wires but when i wiggled the wires at the tb engine stumbled and triggered etc and limp mode this was the primary reason cust. brought car to me .sometimes you can drive for days with no problem other times it will act up again +again HELP