Lumina V6-191 3.1L VIN T MFI (1993)
Oxygen Sensor: Description and Operation
Oxygen Sensor (O2S) - Federal Emissions
Exhaust Oxygen Sensor (02)
PURPOSE:
The oxygen (O2) sensor measures the oxygen content of the exhaust. The ECM monitors the sensor to maintain air/fuel mixture of 14.7 to 1.
OPERATION:
The oxygen sensor monitors atmospheric air versus exhaust gas oxygen content to produce a voltage output. This voltage ranges from
approximately 0.1 volt (high oxygen-lean mixture) to 0.9 volt (low oxygen-rich mixture). By monitoring the oxygen sensor output voltage, the
computer can determine the amount of oxygen in the exhaust gas and adjust the air/fuel mixture accordingly, this is known as "CLOSED LOOP"
operation.
When the sensor is cold it is like an open circuit and produces no voltage below 600°F (315°C). An open sensor circuit or cold sensor causes
"OPEN LOOP" operation.
LOCATION:
Exhaust Manifold