P0101: Mass Air Flow Circuit Range/Performance

Air intakeModerate severity

What P0101 means

The airflow reading does not match what the ECU expects for the current throttle position and engine speed.

Common causes

  • Contaminated MAF sensor element
  • Dirty or over-oiled air filter
  • Air leak in the intake duct after the sensor
  • Restricted exhaust or failing catalytic converter

How it is usually fixed

  1. 1Clean the MAF sensor with dedicated MAF cleaner only
  2. 2Replace the engine air filter and check the intake boot for cracks
  3. 3Compare live airflow readings to the expected value at idle

Other common codes

Code information is general guidance, not a diagnosis for a specific vehicle. Confirm with live data and manufacturer test procedures before replacing parts.