SL L4-1.9L SOHC VIN 9 (1991)
Oxygen Sensor: Description and Operation
Oxygen Sensor Location.
Oxygen Sensor Wiring.
DESCRIPTION
The exhaust gas oxygen sensor, mounted in the exhaust system, monitors the oxygen content of the exhaust gas stream. The exhaust gas oxygen
sensor acts as an electro chemical cell, or battery, to produce a voltage in response to oxygen in the exhaust stream compared to oxygen content of
the atmosphere. A lean mixture (high oxygen in the exhaust gas) produces a low voltage and a rich mixture (low oxygen content in the exhaust
gas) produces a high voltage. The oxygen content in the exhaust reacts with the oxygen sensor to produce a voltage output. The voltage signal
ranges from approximately 100 millivolts (0.1 volt) for a lean mixture to 900 millivolts (0. 9 volt) for a rich mixture.
By monitoring the voltage output of the oxygen sensor, the PCM will know what fuel mixture command is required for the fuel injector (or
injectors).
OPERATING RANGE
The oxygen sensor operates between 275°C (527°F) to 850°C (1562°F).
SENSOR LOCATION
The oxygen sensor is mounted in the exhaust manifold.
GROUND LOCATION
The oxygen sensor ground is located on the back of the engine block.
