Check Engine Code
P0101
Mass Air Flow (MAF) Sensor Circuit Range/Performance
What P0101 means
P0101 sets when the MAF sensor's measured airflow doesn't match what the ECM expects for the current throttle position, RPM, and load. It's typically a dirty sensor or an air leak downstream, not a failed sensor.
Symptoms
- Check engine light
- Rough idle or hesitation on acceleration
- Stalling, especially at low speed
- Noticeable drop in fuel economy
- Black smoke from the exhaust if running rich
Likely causes (most common first)
- Dirty MAF sensor (clean with MAF-specific cleaner, not carb cleaner)
- Unmetered air leak (split intake boot, loose clamp, cracked PCV hose)
- Clogged air filter
- Aftermarket intake installed incorrectly
- Failed MAF sensor element
- Wiring or connector issue at the MAF
Can I keep driving?
Drivable short-term. Running lean (often paired with P0171) can eventually harm the catalytic converter, so don't let it sit for months.
Typical repair cost
DIY fixes can start near $10 (parts only). Shop repairs for P0101 typically run up to $250 depending on the underlying cause and vehicle. Start with the most common cause — Dirty MAF sensor (clean with MAF-specific cleaner, not carb cleaner) — before throwing parts at it.
Related codes
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