P0100 on Your 2022 Toyota Prius
A P0100 code on your 2022 Toyota Prius indicates the ECM has detected a malfunction in the mass air flow (MAF) sensor circuit. As the final year of the 4th-generation Prius, your 2022 model uses the 1.8L Atkinson-cycle hybrid powertrain, where accurate MAF readings are essential for the efficiency Prius owners expect.
Symptoms
- Check engine light on
- Rough idle when gas engine runs
- Hesitation during acceleration
- Noticeably reduced fuel economy
- Gas engine running more frequently
- Possible stalling
Common Causes
- Contaminated MAF sensor (34%) — Oil, dirt, or debris on the sensing element.
- Wiring or connector issues (22%) — Three-plus years of heat and vibration.
- Faulty MAF sensor (18%) — Internal sensor failure.
- Intake air leak (13%) — Cracked boot or loose clamp.
- Air filter restriction (8%) — Overdue filter change.
- ECM issue (5%) — Rare fault.
Diagnostic Steps
- MAF sensor cleaning — Use dedicated MAF cleaner spray.
- Connector inspection — Check for corrosion and looseness.
- Air filter replacement — Fresh paper filter.
- Intake inspection — Check all post-MAF connections.
- Scan tool data — Read MAF values when gas engine is active.
- MAF replacement — If cleaning doesn't resolve the code.
Repair Costs
- MAF cleaning: $10–$15 (DIY)
- Air filter: $12–$25 (DIY)
- MAF sensor: $120–$280
- Intake boot: $60–$170
- Wiring repair: $85–$255
Warranty
Your 2022 Prius's 3-year/36,000-mile warranty extends through 2025. The federal emissions warranty covers the MAF sensor for 8 years/80,000 miles through 2030.