P0171 · blink 25 – SYSTEM TOO LEAN(FUEL TRIM)

System: EFI 3ZZ-FE
Dashboard light: Malfunction indicator lamp (Check Engine)
Check-engine blink code: 25
Applies to: 3ZZ-FE 1.6 (PK SE Saloon 1.6 2002-05 ZZE121)
Description: SYSTEM TOO LEAN(FUEL TRIM)
Detection / symptoms: Detection: Oxygen sensor voltage is 0.45 V or less (lean) for 90 sec. under conditions (a), (b) and (c): (2 trip detection logic) (a) Water temp.: 70˚C (158˚F) or more (b) Engine speed: 1,500 rpm or more (c) Vehicle speed: 100 km/h (62 mph) or less
Possible causes: Air intake (hose loose); Fuel line pressure; Open or short in oxygen sensor circuit; Oxygen sensor malfunction; Air flow meter; Water temp. sensor; Gas leakage on exhaust system
What to check: See RM page (inspection steps not parsed)
Confidence: high (official Toyota RM821E)

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