Fuel and air metering
P0101 — Mass or Volume Air Flow Circuit Range/Performance
The mass air flow (MAF) sensor reading does not agree with what the ECU expects from throttle position and engine speed. The ECU can no longer calculate the right amount of fuel precisely.
Common causes
- Dirty or contaminated MAF sensor element
- Air leak after the MAF sensor (intake hose, boot)
- Clogged air filter or restricted intake
- Faulty MAF sensor
- Exhaust leak affecting oxygen sensors
Symptoms
- Hesitation or poor acceleration
- Rough idle or stalling
- Higher fuel consumption
- Check engine light
How to check
- Inspect the air filter and the intake tract for leaks and loose clamps
- Clean the MAF element with a dedicated MAF cleaner only
- Compare live MAF reading at idle and at 2,500 rpm with the expected values
- Check fuel trims and test the sensor wiring and voltage
Can you keep driving?
Usually drivable, but expect poor performance. Have it fixed soon to protect fuel economy and the catalytic converter.
Related codes
Frequently asked questions
- What causes P0101?
- Most often a dirty MAF sensor or an air leak between the sensor and the engine.
- Can I clean the MAF sensor myself?
- Yes, with a spray made for MAF sensors. Never touch the sensing wire or use other solvents.
General reference information. It does not replace a diagnosis on your own vehicle. The same code can have different causes depending on make, model year and engine; check the manufacturer's documentation or ask a technician with a scan tool.