2002 GMC ENVOY 4.2L While the service engine soon light was on received code p0171 but the light didnt stay on. When going down the highway it loses acceleration and when you try to press the gas its as if it is not evenconnected. It has a rough idle when this occur. If it sits for maybe 30 minutes you can crank it up and drive it like nothing is wrong until you go continuosly for another 15 minutes or so and the problem reoccurs. I have changed the air filter o2 upstream oxygen sensor and fuel filter as suggested but the problem still occurs. If anyone have any suggestion they will be appreciated
Cars & Trucks
Answers & Comments
Your vehicle has electronic throttle control .Position sensors in the gas pedal an throttle postion sensors at the throttle body tell the PCM/ECM -engine computer , how much your foot is pushing on the gas pedal an where the throttle plate is located . These postion sensors wear an can cause this problem ! I suggest you take your vehicle to a qualified repair shop an have it diagnosed .