P0171 · blink 25 – Fuel mixture too lean
- System
- Engine - fuel
- Dashboard light
- Check engine light (MIL)
- Check-engine blink code
- 25
- Applies to
- 1SZ-FE (by platform)
- Description
- Fuel mixture too lean
- Possible causes
- Trouble area: 1.Air leak in intake 2.Blocked or leaking injector 3.Low fuel pressure (pump, filter, regulator) 4.Oxygen sensor
- What to check
- Checking points: 1.Check for vacuum leaks and hoses 2.Check fuel pressure 3.Check injectors 4.Check oxygen sensor
- Confidence
- medium (Toyota Echo 1999–2002 factory diagnostics, same XP10 platform; not confirmed on JDM 1SZ-FE)
From the factory service material. Clear the code and test-drive to confirm it returns. Search all fault codes · Common problems · Warning lights