Oxygen Sensor: Testing and Inspection

The "Scan tool" has several positions that will indicate the state of the exhaust gases, Oxygen voltage, integrator, and block learn.
A problem in the oxygen sensor circuit, or fuel system, should set a DTC 13 (open circuit), DTC 44 (lean indication)/DTC 45 (rich indication). Refer to applicable chart, if any of these DTC(s) were stored in memory.