DR-23 Oxygen Sensor Operation

This test must be performed with engine warm.

1. Connect diagnostic read-out tool to engine harness connector. Ensure read/hold switch is in Read position.
2. Start engine and wait two minutes, then place read/hold switch in Hold position.
3. If display on read-out tool is switching between 0 and 1 or remains on 1, proceed to Test 24. DR-24 Throttle Body Minimum Air Flow
4. If display on read-out tool is 0, check for an engine vacuum leak, a grounded oxygen sensor wire or plugged fuel injector.