P0101 means your mass air flow (MAF) sensor is sending readings outside the expected range for the current engine speed and throttle position. The ECU uses MAF data to calculate fuel injection, so bad readings cause incorrect air-fuel mixture and poor engine performance.
P0101 means your mass air flow (MAF) sensor is sending readings outside the expected range for the current engine speed and throttle position. The ECU uses MAF data to calculate fuel injection, so bad readings cause incorrect air-fuel mixture and poor engine performance.
P0101 is a fuel system-related diagnostic trouble code classified as moderate severity. When your vehicle's ECU detects this condition, it stores P0101 and illuminates the check engine light.
If your vehicle has triggered P0101, you may notice one or more of these symptoms:
Here are the most common causes of P0101, ranked by how likely they are to be the culprit:
Generally yes, for short-term driving. Driveable but engine may run poorly. The ECU uses estimated airflow values when the MAF signal is unreliable, causing rougher idle, hesitation, and worse fuel economy. Safe to drive to a shop.
Follow these steps to pinpoint the root cause of P0101:
Repair costs for P0101 vary depending on the root cause and your vehicle. Here are typical estimates:
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0101 behaves differently depending on your vehicle. Select your car below for model-specific causes, known issues, and adjusted cost estimates:
These codes are often seen alongside P0101 or indicate related issues:
Yes, but the engine may run poorly. The ECU uses estimated airflow when the MAF is unreliable, causing rough idle and hesitation. Safe to drive to a shop.
About 50% of the time, yes. Use dedicated MAF sensor cleaner spray. Costs under 15 euros and takes 10 minutes.
The engine runs on a default airflow table. If it runs better unplugged, the sensor is confirmed bad. Don't drive long distances this way.
Yes. A clogged filter changes airflow velocity across the MAF sensor, pushing readings out of range. Replace the filter first. Costs 10-25 euros.
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