P0101: Mass Air Flow (MAF) Sensor Circuit Range/Performance
The airflow reading does not make sense compared with other sensor readings.
Severity: 2 of 4
Usually drivable but performance may suffer. If the car stalls or hesitates badly in traffic, park it until fixed, because stalling in traffic is a safety risk.
Estimate range covers the repairs listed below; see the cost breakdown. A flashing check engine light, a hot temperature gauge, or brakes that feel different mean stop driving and get help.
What P0101 means
The MAF sensor measures how much air enters the engine so the computer can add the correct amount of fuel. P0101 means its reading is outside the expected range for the current conditions.
A dirty sensor or an air leak between the sensor and the engine are common reasons.
Common causes (cheapest likely first)
- Dirty MAF sensor. Cleaning with dedicated spray is cheap and often works.
- Clogged air filter. Restricts airflow.
- Air leak after the sensor. Loose intake boot or clamp.
- Failed MAF sensor. Replace if cleaning does not help.
- Wiring or connector issue. Corrosion or loose pins.
Symptoms
- Hesitation
- Rough idle
- Stalling
- Poor fuel economy
- Possible lean codes
DIY difficulty: Easy
Cleaning or replacing a MAF sensor is usually a few screws and a connector.
Tools: MAF sensor cleaner, Screwdriver or Torx bits, New air filter
Estimated repair cost
This is an estimate, built from typical parts price ranges plus labor hours times an assumed shop rate of $110 to $190 per hour. Actual prices vary by vehicle, region, and shop. Diagnosis fees are often extra.
| Repair | Parts | Labor | Estimate (low / high) |
|---|---|---|---|
| Air filter | $10 to $40 | 0.1 to 0.3 h | $10 + 0.1 × $110 = $21 $40 + 0.3 × $190 = $97 |
| MAF sensor | $60 to $300 | 0.2 to 0.5 h | $60 + 0.2 × $110 = $82 $300 + 0.5 × $190 = $395 |
| Intake boot | $20 to $120 | 0.3 to 1.0 h | $20 + 0.3 × $110 = $53 $120 + 1.0 × $190 = $310 |
Watch a repair video
Search YouTube for “P0101 fix” videos. Pick a recent video that matches your engine, and confirm the diagnosis before buying parts.
By make
This code works the same way on every make. See brand notes.
Repair manuals
Step-by-step service manuals with torque specs and wiring diagrams:
Haynes manuals Chilton manuals
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Related codes
Check for recalls
Before paying for a repair, enter your VIN in the NHTSA recall lookup. Emissions parts may also be covered by a federal emissions warranty; check your warranty booklet.
FAQ
Can I clean a MAF sensor with brake cleaner?
Do not. Use cleaner made for MAF sensors and never touch the sensing element.
Do oiled air filters cause P0101?
Over oiled filters can contaminate the sensor.