DTC 70: Oxygen Sensor: Troubleshooting

Observe emission control and sensor voltage with scan tool. After sensor has reached operating temperature, the sensor voltage should be .02-.085 volt.

• If sensor voltage is not okay, detach connector for oxygen sensor, switch on ignition and measure voltage at the connector (control unit side). Voltage should be .45 volt.
• Check wire and oxygen sensors.
• If oxygen sensors have been interchanged (DME control unit I operates with sensor II and vice versa), this defect code will be stored in both control units. The mixture is too rich in one group of cylinders and too lean in the other. See OXYGEN SENSOR  under COMPONENT TESTS.