Rear

When using scan tool MB991502, observe HO2S reading. If values are unsatisfactory or if the scan tool is not available, use the following procedure:




1. Disconnect the heated oxygen sensor connector and connect special tool
MB991658 to the connector on the heated oxygen sensor side.
2. Make sure that there is continuity [11 - 18 ohms at 20°C (68°F)] between terminal 3 and terminal 4 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 3 of the heated oxygen sensor connector to the positive battery terminal and terminal 4 to the negative battery terminal.
6. Connect a digital voltage meter between terminal 1 and terminal 2.

Standard Value:

7. While repeatedly revving the engine, measure the heated oxygen sensor output voltage.
8. 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.