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Trouble code libraryFuel and air

P0101 Air flow sensor reading is off

Generic SAE definitionMass air flow circuit range/performance

Drive gentlyYou can drive it, but take it easy and get it looked at soon – waiting usually makes the repair bigger.

Check this first

Look for a loose or split air intake hose between the filter box and the engine, and a dirty air filter.

What usually fixes it

In the order a good shop checks them. Typical total: $52–$418 at $130 an hour.

  1. Clean the air flow sensor

    $52–$85

    Dust and oil film on the sensor wire make it under-read.

  2. Air filter and intake hose

    $87–$218

    A split hose lets in air the sensor never measured.

  3. Mass air flow sensor

    $112–$401

    The sensor drifts with age and can't be cleaned back.

Code titles are the generic SAE definitions. Prices are typical US parts and labor for a common car or light truck – a guide for judging a quote, not a quote. Always confirm a repair against the vehicle in front of you.

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See what your vehicle says about P0101

A stored code is a headline, not the story. The vehicle also holds the conditions from the moment the code set, how close each part is to the limit it fails at, what the fuel trims are doing, and whether the fault is still happening. Drive DTC reads all of it with a USB adapter and a Windows PC – read-only by design.

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The Trouble codes screen in Drive DTC: stored, pending and permanent counts, then C0040-13 explained in plain English with what to check first, likely fixes in order and typical cost ranges

More in Fuel and air

All 73 codes in this group
P0100Mass air flow circuit P0102Mass air flow circuit low P0103Mass air flow circuit high P0106Manifold absolute pressure/barometric pressure circuit range/performance P0107Manifold absolute pressure/barometric pressure circuit low P0108Manifold absolute pressure/barometric pressure circuit high