Heated Oxygen Sensor: Tacoma
WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 2003 Toyota Tacoma, 2003 Toyota RAV4, 2003 Toyota Prius, 2003 Toyota Matrix, and 2003 Toyota MR2. However, it is still accessible from the selected car via links, so may be relevant.
- A heated Air/Fuel (A/F) sensor is mounted on exhaust pipe in front of catalytic converter. For testing of A/F sensor, see AIR/FUEL SENSOR . A heated oxygen sensor is mounted on exhaust pipe behind catalytic converter. This oxygen sensor is referred to as bank No. 1 sensor No. 2, or rear oxygen sensor.
- To test heater resistance on heated oxygen sensor, disconnect electrical connector for heated oxygen sensor. Using ohmmeter, check resistance between +B and HT terminals on electrical connector. See Fig 1. Replace heated oxygen sensor if resistance is not 11-16 ohms at 68°F (20°C) and 23-32 ohms at 1472°F (800°C). See HEATED OXYGEN SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL & INSTALLATION - 4-CYLINDER article.
- If problem exists in either heated oxygen sensor, heater or wiring circuit, a Diagnostic Trouble Code (DTC) may be stored in Engine Control Module (ECM). See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.