Contents: Examination ⇓ Replacement ⇓
The oxygen sensor checks the oxygen content in the exhaust gases. Based on information from the oxygen sensor, the electronic control unit regulates the composition of the fuel mixture.
Examination
1. To check the primary sensor (located in front of the catalytic converter) connect the positive probe of the voltmeter to the signal terminal of the sensor and the negative probe to the ground terminal.
2. Start the engine and check that the voltage between the terminals is 0.1-0.2 volts while the engine is cold (the engine is running in open mode). After about two minutes, the engine and oxygen sensor should warm up and the voltage should begin to fluctuate between 0.1 and 0.9 volts (the electronic control unit has entered closed mode of operation).
3. Check that the sensor's heating element resistance is 10–40 ohms. Check the voltage supply to the heating element.
4. Replace the oxygen sensor if it is faulty.
Replacement
1. Disconnect the sensor connection connector and carefully unscrew the sensor.
2. Lubricate the threads of the new sensor with an anti-corrosion compound before installation. Installation is carried out in the reverse order of removal.