Inspection Of Front & Rear Heated Oxygen Sensor Heaters

Ensure ignition switch is OFF.
Disconnect heated oxygen sensor connector.
Connect ohmmeter between terminals 1 and 3 and measure resistance.
Specification: Approx. 2~4Ω (68°F {20°C})

Fig 1: Locating Oxygen Sensor Connector Terminals
Courtesy of KIA MOTORS AMERICA, INC.

Fig 2: Testing Oxygen Sensor Resistance
Courtesy of KIA MOTORS AMERICA, INC.
If not as specified, replace heated oxygen sensor.
Tightening Torque:
1. 22-36 lb-ft (30~49 N.m, 3~kg-m)
Reconnect heated oxygen sensor connector.