Aurora V8-4.0L VIN C (1996)
Oxygen Sensor: Description and Operation
DESCRIPTION
Four oxygen sensors are mounted in the exhaust system where they monitor the oxygen content in the exhaust stream. There is an oxygen sensor
mounted in each exhaust manifold and one on each end of the catalytic converter. The oxygen sensor located in the front exhaust manifold is the Bank
2 Sensor 1 (Front) sensor. The oxygen sensor located in the rear exhaust manifold is the Bank 1 Sensor 1 (Rear) sensor. The oxygen sensor located in
the Y-pipe ahead of the catalytic converter is the Bank 1 Sensor 2 (Pre-converter) sensor. The oxygen sensor located in the catalytic converter outlet is
the Bank 1 Sensor 3 (Post-converter) sensor.
OPERATION
An oxygen sensor acts like a battery because it creates its own signal voltage once it reaches operating temperature. This voltage is produced when the
oxygen content in the exhaust stream is different than the oxygen content in the atmosphere. A lean condition (high oxygen content in exhaust) will
produce a low voltage (near 0 volt) and a rich condition (low oxygen content in exhaust) will produce a high voltage (near one volt). The PCM
provides a reference signal voltage (0.45 volt) and a ground to the sensor. The PCM reference voltage is necessary because the oxygen sensors do not
provide their own voltage until they reach operating temperature.
OXYGEN SENSOR HEATER
The oxygen sensors also incorporate a heating element inside of the sensor housing. This heating element is energized with the ignition On and allows
the sensors to reach operating temperatures quickly. The PCM can then use oxygen sensor information sooner after engine startup.
OXYGEN SENSOR INFORMATION USE
The PCM uses oxygen sensor information during Closed Loop operation to constantly adjust fuel control to reduce exhaust emissions. Because the
oxygen sensors provide information sooner after engine startup, exhaust emissions are reduced. Faulty oxygen sensors will cause various driveability
conditions and will set a DTC.
