Diagnostic Test Mode 2-Heated O2 Sensor Monitor

Heated Oxygen Sensor Test Table:

OPERATION
In this mode, the MALFUNCTION INDICATOR LAMP and RED LED display the condition of the fuel mixture (lean or rich) which is monitored by the heated oxygen sensor.

HOW TO CHECK HEATED OXYGEN SENSOR
1. Set Diagnostic Test Mode II. (Refer to "HOW TO SWITCH MODES".)
2. Start engine and warm it up until engine coolant temperature indicator points to the middle of the gauge.
3. Run engine at about 2,000 rpm for about 2 minutes under no-load conditions.
4. Make sure RED L.E.D. or MALFUNCTION INDICATOR LAMP goes ON and OFF more than 5 times every 10 seconds; measured at 2,000 rpm under no-load.