Oxygen Sensor: Description and Operation

Oxygen Sensors:

The oxygen sensors are exhaust mounted measuring devices for determining the oxygen content in the exhaust gases. Since the amount of oxygen in the exhaust indicates precisely how complete the combustion of the air/fuel mixture in the cylinders is, it is also a good indicator of the air/fuel ratio. The voltage signals generated by the oxygen sensors are sent to the ECU through terminals OX1 and OX2. The ECU uses these signals to enrichen or lean the fuel mixture accordingly. The higher the voltage output by the OS, the richer the sensed signal to the ECU and the more the ECU will lean the fuel input. The lower the voltage output by the OS, the leaner the sensed signal to the ECU and the more the ECU will increase injection pulse width. This will enrich the air/fuel mixture to the engine.
This vehicle utilizes two oxygen sensors, (one in each exhaust passage), to regulate air/fuel mixture through the ECU. Both oxygen sensors are equipped with internal heater elements to aid with efficiency and faster sensor warm-up.