Oxygen Sensor: Testing and Inspection

Inspection

1. Warm up the engine and run it at idle.






2. Disconnect the connector of oxygen sensor wiring harness.

3. Connect a voltmeter between the oxygen sensor connector (A) and (B) (oxygen sensor side).

4. Increase and decrease the engine speed suddenly several times. When the speed is increased, check that the meter reads between O.5V-1.OV.

When the speed is decreased, check that it reads between
OV-0.4V.

5. If not as specified, replace the oxygen sensor.









Inspection of Sensitivity

1. Warm up the engine and run it at idle.

2. Connect the SST to the check connector.


Note

Do not ground the test connector (Green: 1-pin) while inspecting the oxygen sensor sensitivity.



3. Increase the engine speed to between 2,00O and 3,000 rpm, and check that the monitor lamp flashes for 10 seconds.


Monitor lamp: Flashes ON and OFF more than 8 times/10 sec.







Inspection of heater

1. Disconnect the connector of oxygen sensor wiring harness.

2. Connect an ohmmeter between (D) and (C) terminals (oxygen sensor side) and check for continuity.

3. If there is no continuity. replace the oxygen sensor.







Replacement

1. Disconnect the connector.

2. Remove the oxygen sensor and gasket.

3. Install the oxygen sensor and a new gasket.


Note

When installing the oxygen sensor, tighten to the specified torque.


Tightening torque:

29-49 Nm (3-5 m-kg, 22-36 ft-lb)