5. Monitor The O2 Sensors

With the engine running.

With the DRB III(R), actuate the Air Pump Relay.

Monitor the voltage on both front O2 sensors.

Fig 1: Monitoring O2 Sensor Voltage

Courtesy of DAIMLERCHRYSLER CORP.

Does the O2 sensor voltage for both sensors drop to less than 0.1 volts? 

1. Yes  >> Go To 12 
2. No  >> Remove the Switchover Valve for the affected bank and inspect for damage or restrictions. If no problems are found, replace the Switchover Valve. See EMISSIONS CONTROL article.

   See POWERTRAIN VERIFICATION TEST - VER 2  .