1. O2 Heater Element

NOTE: Allow the O2 Sensor to cool down to room temperature.

Turn the ignition off.

Disconnect the O2 Sensor harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance of the O2 Sensor Heater element at the O2 Sensor harness connector.

Fig 1: Measuring Resistance Of O2 Sensor Heater Element At O2 Sensor Harness Connector

Courtesy of DAIMLERCHRYSLER CORP.

Is the O2 Sensor Heater element resistance between 8.5 and 9.5 ohms?

Yes >> Go To 2
No >> Replace the Oxygen Sensor. See FUEL SYSTEM article.
See POWERTRAIN VERIFICATION TEST - VER 2 .