P0130 · blink 21 – OXYGEN SENSOR CIRCUIT MALFUNCTION(BANK1 SENSOR1)

System: EFI 3ZZ-FE
Dashboard light: Malfunction indicator lamp (Check Engine)
Check-engine blink code: 21
Applies to: 3ZZ-FE 1.6 (PK SE Saloon 1.6 2002-05 ZZE121)
Description: OXYGEN SENSOR CIRCUIT MALFUNCTION(BANK1 SENSOR1)
Detection / symptoms: Detection: Condition (a) and (b) continues for 60 secs. or more: (c) Voltage output of oxygen sensor remains at 0.35 V or more, or 0.55 V or less, during idling after engine is warmed up (d) Oxygen sensor output voltage amplitude is less than 0.3 V.
Possible causes: Oxygen sensor; Fuel trim malfunction
What to check: See RM page (inspection steps not parsed)
Confidence: high (official Toyota RM821E)

From the factory service material. Clear the code and test-drive to confirm it returns. Search all fault codes · Common problems · Warning lights