What are the common causes of P0101?

Dirty or contaminated mass air flow (MAF) sensor. Clogged or leaking air intake duct between filter and sensor. Vacuum leak downstream of the MAF sensor. Damaged MAF sensor wiring or connector. Faulty mass air flow sensor or PCM.

Inspect and clean the MAF sensor with MAF-specific cleaner. Check the air intake duct for cracks, leaks, and loose clamps. Visually inspect MAF sensor wiring and connector for damage. Monitor MAF grams-per-second readings with an OBD-II scanner at idle and 2500 rpm. Replace the MAF sensor if readings are out of spec after cleaning.

P0101

Mass or Volume Air Flow Circuit Range/Performance Problem

System: Fuel and air metering (P code)
Lamp: Check Engine Light
Category: Powertrain - Fuel/Air Metering

What it means

P0101 means Mass or Volume Air Flow Circuit Range/Performance Problem.

Check these first

Dirty or contaminated mass air flow (MAF) sensor
Clogged or leaking air intake duct between filter and sensor
Vacuum leak downstream of the MAF sensor
Damaged MAF sensor wiring or connector
Faulty mass air flow sensor or PCM

What to do next

Inspect and clean the MAF sensor with MAF-specific cleaner
Check the air intake duct for cracks, leaks, and loose clamps
Visually inspect MAF sensor wiring and connector for damage
Monitor MAF grams-per-second readings with an OBD-II scanner at idle and 2500 rpm
Replace the MAF sensor if readings are out of spec after cleaning

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Updated

Generic SAE J2012 definition. Last updated 2026-08-30.