P0101: Mass Air Flow Sensor Problem
P0101 means the mass air flow (MAF) sensor reading is outside the expected range — the measured air amount does not match what is expected, confusing fuel-mixture calculations.
Symptoms
Rough idle, hesitation/weakness on acceleration, higher fuel use, sometimes hard starting, with a check engine light.
Common causes
A dirty MAF sensor (most common — dust/oil on the hot wire), a dirty air filter, an air leak after the sensor, or a failed sensor.
The fix
Clean the MAF with dedicated cleaner (do not touch the wire), change the air filter, and check for air leaks. Live air-flow data via OBD2 reveals the abnormal value.
FAQ
Is cleaning the MAF enough?
Often yes — fouling is a common cause. If the code stays after cleaning and the filter, the sensor may be failed or there is an air leak.
Can I drive with P0101?
Short-term yes, but it raises fuel use and weakens performance — address it soon.