On-Vehicle Inspection

WARNING: This page is about a different car, the 2006 Lexus IS 350. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT HEATED OXYGEN SENSOR
1. Disconnect the sensor connector.
2. Measure the heater resistance between terminals 1 (HT) and 2 (+B) of the sensor.
  Standard resistance: 5 to 10 Ω at 20°C (68°F)
  
  If the result is not as specified, replace the sensor.
  
  Fig 1: Identifying Heated Oxygen Sensor Connector Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002