Front
HEATED OXYGEN SENSOR CHECKRequired Special Tools:
MD998464: Test Harness
MB991316: Test Harness
MB991 658: Test Harness Set
When using Scan tool, observe HO2S reading. If values are unsatisfactory, or if 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 Ohm 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 battery (+) terminal and terminal 4 to the battery (-) terminal.
6. Connect a digital voltage meter between terminal 1 and terminal 2.
7. While repeatedly rewing the engine, measure the heated oxygen sensor output voltage.
Standard value:
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.