Front oxygen sensor
1. Disconnect the oxygen sensor connector and connect a special tool to the connector on the sensor side (test lead harness).
2. Check that the circuit between terminal 1 and terminal 3 of the oxygen sensor connector is closed (resistance between terminals is 4.5-8 Ohm at 20°C).
3. If the circuit is broken, replace the oxygen sensor.
4. Warm up the engine to a coolant temperature of 80°C or higher.
5. Set the engine speed to 4500 rpm for 5 minutes.
6. Connect digital (electronic) voltmeter to terminals 2 and 4 of the sensor connector.
The material was copied from the website [mitsubishiman.ru]
7. Periodically pressing the accelerator pedal, measure the output voltage of the oxygen sensor.
Good condition:
| Engine | Oxygen sensor output voltage | Note |
| When you press the accelerator pedal | 0.6-1.0 V | If you enrich the fuel-air mixture by periodically pressing the accelerator pedal, then a working oxygen sensor will output a voltage of 0.6-1.0 V. |
8. If the oxygen sensor is faulty, replace it.
Note: For removal and installation of the oxygen sensor, see Section "Exhaust pipe and main muffler".