HO2S Sensor 1

The scan tool displays Not Ready or Ready. Indicates the status of the fuel control exhaust oxygen sensor. The scan tool will indicate that the exhaust oxygen sensor is ready when the PCM detects a fluctuating HO2S voltage sufficient to allow closed loop operation. This will not occur unless the exhaust oxygen sensor is warmed up.

The scan tool range is 0-1000 mV. The HO2S mV sensor 1 parameter represents the fuel control exhaust oxygen sensor output voltage. The voltage should fluctuate constantly within a range between about 50 mV (lean exhaust) and 800 mV (rich exhaust) while operating in Closed Loop.