P0101 — Mass Air Flow (MAF) Circuit Range/Performance
Drive with caution — fix soon.
What P0101 means
This code means your car's computer noticed the mass air flow sensor is reporting a value that doesn't match what the engine is actually doing. The MAF sensor measures how much air enters the engine so the right amount of fuel can be added. When its signal is off, the air-fuel mix gets thrown out of balance.
Common symptoms
- Check Engine light is on
- Rough or uneven idle
- Hesitation or stumbling when accelerating
- Noticeably worse fuel economy
- Engine feels down on power
Common causes
- Dirty or contaminated MAF sensor element
- Vacuum or intake air leak after the sensor
- Damaged or loose air intake hose or boot
- Clogged or improperly installed air filter
- Faulty MAF sensor
- Wiring or connector problems in the MAF circuit
Typical repair cost
$80 – $350
Varies by vehicle and root cause.
Frequently asked questions
Can I drive with a P0101 code?
For short trips, usually yes, but the engine may run poorly and waste fuel. It's best to get it diagnosed within a few days so a small issue doesn't grow into a bigger one.
How much does it cost to fix P0101?
Often between $80 and $350. Simply cleaning the MAF sensor or fixing a loose hose is cheap, while replacing the sensor itself costs more.
Is P0101 a serious problem?
It's moderate. Your car won't break down immediately, but ignoring it can lead to poor performance, higher fuel use, and added wear on the engine over time.
Can a dirty air filter cause P0101?
Yes. A clogged filter or one that lets dirt onto the MAF sensor can throw off its readings. Cleaning the sensor and replacing a dirty filter often resolves the code.