Anonymous asked in Cars & TransportationCar MakesGMC · 3 months ago

GMC Sierra misfire?

I have a 2004 Sierra 2500 with a 6.0 vortec. Mainly throws the code p0101 like it says rn. And sometimes will throw p0171 or p0174 but mainly the first one.  It happens maybe half the time it will sputter and says it's running lean. I did do a smoke test so no vaccum leaks and I did put a good mass airflow sensor in. New plugs and wires two months ago. As with everyone we all know generic codes can be a pain in the rear. Any help is appreciated thanks

3 Answers

  • Anonymous
    3 months ago
    Favourite answer

    You will need a scanner that can check MAF sensor values.  Also check for power, ground and sensor output wires on the MAF sensor.  There could be a bad connector or a bad wire in the MAF sensor.  Good luck.

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  • 3 months ago

    You did not say what the mileage is on the engine.

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  • 3 months ago

    With those codes it's likely you still have an issue with the MAF sensor. You meed to take the harness connector off at the MAF and check that the terminals are tight and have enough tension on the MAF pins. I'd find a mechanic scan tool that reads sensor voltages and shake down the MAF harness while monitoring the voltages to see if they change. You can find average MAF sensor voltage readings for your motor on youtube.

    Source(s): Mitsubishi Master Tech
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