Montero Sport LTD 4WD V6-3.5L SOHC (1999)
Oxygen Sensor: Testing and Inspection
Front
HEATED OXYGEN SENSOR CHECK
Required Special Tools:
MB991316: Test Harness
MD998464: Test Harness
<Heated oxygen sensor (front) - Federal and right bank heated oxygen sensor (front) - California)>
1. Use Scan tool, observe HOBS reading. If values are unsatisfactory, or it Scan tool is not available, use the following procedure:
1. Disconnect the heated oxygen sensor connector and connect special tool MD998464 to the connector on the heated oxygen sensor side.
2. Make sure that there is continuity [7 - 40 Ohm at 20 °C (68 °F)] <Federal>, 4.5 - 8.0 Ohm at 20 °C (68 °F) <California> between terminal 1
(red clip of special tool) and terminal 3 (blue clip of special tool) on the heated oxygen sensor connector.
3. If there is no continuity, replace the heated oxygen sensor.
4. Warm up the engine until engine coolant is 80 °C (176 °F) or higher.
CAUTION: Be very careful when connecting the jumper wires; incorrect connection can damage the heated oxygen sensor.
5. Use the jumper wires to connect terminal 1 (red clip) of the heated oxygen sensor connector to the battery (+) terminal and terminal 3 (blue
clip) to the battery (-) terminal.
6. Connect a digital voltage meter between terminal 2 (black clip) and terminal 4 (white clip).
2. While repeatedly racing the engine, measure the heated oxygen sensor output voltage.
Standard value:
3. If the sensor is defective, replace the heated oxygen sensor.
NOTE: For removal and installation of the heated oxygen sensor; refer to Exhaust Pipe and Main Muffler.
