On-Vehicle Inspection

WARNING: This page is about a different car, the 2007 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.

CHECK AIR FUEL RATIO SENSOR
1. Disconnect the sensor connector.
2. Measure the heated resistance between terminals 1 (HT) and 2 (+B) of the sensor.
  Standard resistance: 1.8 to 3.4 Ω at 20°C (68°F)
  
  If the result is not as specified, replace the sensor.
  
  Fig 1: Identifying Air Fuel Ratio Sensor Connector Terminal
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002