CarSense › Trouble codes › P0101

P0101: Mass or Volume Air Flow Circuit Range/Performance Problem

What this check-engine code means in plain English, what usually causes it, and what a fix typically costs.

Severity: Monitor — not an emergency, but address soon

What P0101 means

The Mass Air Flow (MAF) sensor measures how much air enters the engine so the computer can adjust fuel delivery. This code means the MAF sensor's readings are outside the expected range or don't match what other sensors are reporting, causing the computer to detect an inconsistency in airflow data.

What causes P0101?

Likely
Dirty or contaminated MAF sensorOil, dirt, or debris on the sensor element causes inaccurate readings and is the most common trigger for this code.
Likely
Air leaks after the MAF sensorCracks in intake hoses, loose clamps, or vacuum leaks allow unmetered air into the engine, skewing the sensor data.
Possible
Failing MAF sensorThe sensor itself may be wearing out or damaged, providing erratic or out-of-range voltage signals to the computer.
Less common
Clogged air filter or restricted intakeA severely dirty air filter or blocked intake can restrict airflow enough to cause performance issues and trigger this code.

Is P0101 safe to drive?

Drive it?
Usually yes, short-term
Watch for
Poor fuel economy, rough idle, hesitation, or stalling
DIY-friendly?
Cleaning the MAF sensor is straightforward; leak checks require patience

You can typically drive with this code in the short term, but expect reduced fuel economy and performance issues like hesitation or rough running. The engine may run rich or lean, which can damage the catalytic converter over time if ignored, so address it within a few weeks.

P0101 repair cost

~$50 – $400+

Industry-average estimates. Cost depends on whether cleaning the sensor solves it (minimal cost) or if sensor replacement and labor are needed.

Which one is it for your car?

Plug a cheap OBD2 adapter into your car and CarSense reads your codes and tells you the likely cause and a real cost for your exact vehicle — free to scan, no proprietary dongle.

Download for iPhoneGet it on Android

Related codes

P0102P0171