P0101: Mass Air Flow (MAF) Sensor Circuit Range/Performance
Your mass air flow sensor is giving readings outside the expected range. The MAF measures how much air enters the engine so the computer can add the right amount of fuel. A bad reading means incorrect fuel delivery.
Symptoms
- Check engine light
- Hard starting
- Rough idle
- Hesitation or surging
- Black smoke from exhaust (running rich)
Causes (Ranked by Likelihood)
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DIY Fix Steps
⚠ Safety first: work on a cold engine, chock wheels, use jack stands - never rely on a floor jack alone.
This fixes 50%+ of P0101 codes. Disconnect battery for 15 min first. Remove MAF (2 screws). Spray MAF cleaner 10-12 times on sensing wires. Air dry 30 min. Reinstall.
A severely clogged filter restricts airflow below MAF measurement range. Check if dirty, replace if needed ($10-25).
Check rubber intake hose from air box to throttle body for splits, tears, or loose clamps. Unmetered air bypasses the MAF.
If code returns after cleaning, replace the MAF sensor. Buy OEM or high-quality aftermarket ($30-120). Generic eBay sensors often trigger same code.