OBD-II code guide

P0101 Mass Airflow Sensor Range or Performance

P0101 means the MAF sensor reading is outside the range the computer expects.

What it means

The measured airflow does not match engine operating conditions.

Common symptoms

  • Hesitation
  • Poor acceleration
  • Rough idle
  • Stalling
  • Lean or rich codes

Likely causes

  • Dirty MAF sensor
  • Intake air leak
  • Clogged air filter
  • Wiring issue
  • Aftermarket intake airflow turbulence

First checks

  • Inspect intake ducts after the MAF.
  • Check air filter fitment.
  • Look for P0171 or P0174.
  • Clean only with MAF-safe cleaner if appropriate.