Grand AM L4-138 2.3L DOHC VIN D MFI (1994)
Oxygen Sensor: Description and Operation
Exhaust Oxygen Sensor (02)
PURPOSE
The oxygen (O2) sensor measures the oxygen content of the exhaust. The PCM monitors the sensor to maintain air/fuel mixture of 14.7 to 1.
LOCATION:
Exhaust Manifold
OPERATION
The PCM supplies a voltage of about .45 volt between the sensor and ground. (If measured with a 10 megaohm digital voltmeter may read as low as
.32 volt). The O2 sensor varies the voltage within a range of about 1 volt if the exhaust is rich, down to about .10 volt if the exhaust is lean.
The sensor is an like open circuit and produces no voltage below 600~F (315~C). An open sensor circuit or cold sensor causes "Open Loop"
operation.
