K 1500 Truck 4WD V8-305 5.0L VIN M SFI (1996)
Oxygen Sensor: Description and Operation
Heated Oxygen Sensor (HO2S) Cutaway
OPERATION
To control emissions of Hydrocarbons (HO), Carbon Monoxide (CO), and Oxides of Nitrogen (NOx), a three-way catalytic converter is used. The
catalyst within the converter promotes a chemical reaction which oxidizes the HO and CO present in the exhaust gas, converting them into
harmless water vapor and carbon dioxide. The catalyst also reduces NOx, converting it to nitrogen. The VCM has the ability to monitor this
process using the Bank 1 Sensor 2 and the Bank 1 Sensor 3 heated oxygen sensors. The Bank 1 Sensor 2 sensor produces an output signal which
indicates the amount of oxygen present in the exhaust gas entering the three way catalytic converter. The Bank 1 Sensor 3 sensor produces an
output signal which indicates the oxygen storage capacity of the catalyst; this in turn indicates the catalyst ability to convert exhaust gases
efficiently. If the catalyst is operating efficiently, the Bank 1 Sensor 2 sensor will produce a far more active signal than that produced by the Bank
1 Sensor 3 sensor.
