OBD2 Code P0101: Mass Air Flow (MAF) Sensor Circuit Range/Performance
The P0101 code means Mass Air Flow (MAF) Sensor Circuit Range/Performance. Estimated repair cost: $80 – $400.
✅ OK TO DRIVE (short term). Have it diagnosed at your next convenience. Monitor for new symptoms.
📋 Diagnostic Reference
| OBD2 Code | P0101 |
| Category | Powertrain |
| Severity | Check Soon |
| Repair Cost | $80 – $400 |
| Can You Drive? | ✅ Yes — diagnose at your convenience |
🔍 Symptoms
- Check Engine Light on
- poor fuel economy
- hesitation on acceleration
- rough idle
- black smoke from exhaust
⚠️ Most Likely Causes (in order of probability)
- Dirty or contaminated MAF sensor
- vacuum leak after MAF
- faulty MAF sensor
- intake air leak
- wiring issue
🛠️ Diagnostic Procedure
Step 1: Inspect MAF sensor for dirt or contamination — clean with MAF cleaner
Inspect MAF sensor for dirt or contamination — clean with MAF cleaner
Step 2: Check for vacuum leaks after the MAF sensor
Check for vacuum leaks after the MAF sensor
Step 3: Compare actual vs reported airflow with scan tool
Compare actual vs reported airflow with scan tool
Step 4: Check MAF sensor wiring and connector
Check MAF sensor wiring and connector
Step 5: Replace MAF sensor if cleaning doesn't resolve.
Replace MAF sensor if cleaning doesn't resolve.
ASE Certified Review: This diagnostic guide has been reviewed by an ASE-certified master technician. Diagnostic steps follow industry best practices per SAE J1979 and OEM service procedures. Always verify with a qualified mechanic before performing repairs.
Technician's Notes: MAF sensor cleaning is the first step — it fixes about 60% of P0101 codes. Use ONLY MAF cleaner spray, never carb cleaner.
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Data Sources: Diagnostic information compiled from SAE J1979 OBD2 standards, OEM service manuals, and ASE master technician field experience. Reviewed for technical accuracy. Repair cost ranges are national estimates and vary by location. Always verify with a qualified mechanic.