I have an 07 gmc envoy 4.2 I6 4wd with 165k miles. No codes showing when scanned.
So on cold mornings it will start up immediately then rpms jump around for a few seconds then dies. It does this whether I give it gas or not until it gets a little warmth to it. I have replaced the MAF, MAP, and temperature sensors, intake manifold gasket, and throttle body. It has recently also had air filter, spark plugs, and battery replaced. I have tested fuel pressure, the fuel injectors and vacuum pressure. The O2 sensors are reading within tolerance.
I am rather lost on what else the problem could be. Any advice at this point would be greatly appreciated.
So on cold mornings it will start up immediately then rpms jump around for a few seconds then dies. It does this whether I give it gas or not until it gets a little warmth to it. I have replaced the MAF, MAP, and temperature sensors, intake manifold gasket, and throttle body. It has recently also had air filter, spark plugs, and battery replaced. I have tested fuel pressure, the fuel injectors and vacuum pressure. The O2 sensors are reading within tolerance.
I am rather lost on what else the problem could be. Any advice at this point would be greatly appreciated.