FixVault

Air-Fuel Ratio (A/F) Sensor: Inspection

  1. INSPECT HEATER RESISTANCE OF A/F SENSOR (Bank 1 Sensor 1) 
    1. Disconnect the sensor connector.
    2. Using an ohmmeter, measure the resistance between terminals +B and HT.
      Fig 1: Measuring Resistance Between Terminals +B And HT
      G04208021Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Resistance: 

      RESISTANCE CHART

      20°C (68°F) 0.8 - 1.4 Ω
      800°C (1,472°F) 1.8 - 3.2 Ω

      If the resistance is not as specified, replace the sensor.

      Torque: 20 N.m (200 kgf.cm, 14 ft.lbf) 

    3. Reconnect the sensor connector.
  2. INSPECT OPERATION OF A/F SENSOR (See  DTC P2195: OXYGEN (A/F) SENSOR SIGNAL STUCK LEAN  and  DTC P2238: OXYGEN SENSOR PUMPING CURRENT CIRCUIT LOW/HIGH  )