Heated Oxygen Sensor (Ho2S): Inspection

NOTE:

Before checking, warm up the engine until the engine coolant temperature reaches 80 to 95°C (176 to 205°F).
Use an accurate digital voltmeter.

Disconnect the oxygen sensor connector, and measure the resistance between terminal 3 and terminal 4.

Fig 1: Standard Value Table
Courtesy of HYUNDAI MOTOR CO.

Fig 2: View Of Heated Oxygen Sensor
Courtesy of HYUNDAI MOTOR CO.
Replace the oxygen sensor if there is a malfunction.
Apply battery voltage directly between terminal 3 and terminal 4.
NOTE: Be careful when applying the voltage. Damage will result if terminals 1 and 2 are connected to any voltage
Connect a high-impedance digital-type voltmeter between terminal 1 and terminal 2.

Fig 3: View Of Heated Oxygen Sensor Harness Side Connector
Courtesy of HYUNDAI MOTOR CO.
While repeatedly racing the engine, measure the oxygen sensor output voltage.

Fig 4: Oxygen Sensor Output Voltage Table
Courtesy of HYUNDAI MOTOR CO.

Fig 5: Oxygen Sensor Output Voltage Wave Form
Courtesy of HYUNDAI MOTOR CO.

Fig 6: Oxygen Sensor Output Voltage Graph
Courtesy of HYUNDAI MOTOR CO.
If there is a problem, there may be an oxygen sensor malfunction.
Tightening torque

Heated oxygen sensor:

40~50 Nm (400~500 kg.cm, 29~36 lb.ft)

Fig 7: Heated Oxygen Sensor Side Connector

Courtesy of HYUNDAI MOTOR CO.