Eclipse FWD L4-1997cc 2.0L DOHC MFI (1997)
Heated Oxygen Sensor (HO2S): Testing and Inspection
Heated oxygen sensor (front)
1. Disconnect the heated oxygen sensor connector.
2. Check that there is continuity 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° (176°F) or higher.
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.
CAUTION: Be very careful when connecting the jumper wires, or the heated oxygen sensor can be damaged.
6. Connect a digital voltmeter between terminal 1 and terminal 2.
7. While repeatedly racing 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, Main Muffler.
