Summit Wagon AWD L4-1795cc 1.8L SOHC (1994)
Oxygen Sensor: Description and Operation
PURPOSE
The oxygen (O2) sensors are mounted in the exhaust system, and monitor the amount of oxygen in the exhaust gas. The sensor has a closed tube
made of ceramic zirconia.
OPERATION
The difference in the amount of oxygen contacting the inner and outer surfaces of the oxygen sensor creates a pressure differential which results in
a voltage signal being generated. The amount of voltage produced is determined by combustion efficiency.
Voltage output from the Oxygen Sensor can reach 0.9 volts DC when the fuel air mixture is too rich and about 0.1 volts DC when the mixture is
too lean, with a sharp voltage transition from high to low at the stoichiometric point.
To aid quick warm-up, thus entering closed loop operation sooner (subsequently reducing exhaust emissions) this vehicle is equipped with an
electrically heated oxygen sensor.
Oxygen Sensor Voltage vs Fuel/Air Ratio
The ECM's instant mixture adjustment in response to the voltage output of the oxygen sensor causes the output voltage from the Oxygen Sensor to
fluctuate rapidly between 0.1 and 0.9 volts DC and will be observed as an average of about 0.6 volts DC when measured with a voltmeter.
Oxygen Sensor
Catalytic Converter Performance
CONSTRUCTION
