S 320 SWB (140.032) L6-3.2L (104.994) (1994)
Oxygen Sensor: Description and Operation
Oxygen Sensor I and II
Oxygen Sensor (Three-Wire Type)
Oxygen Sensor With Internal Heater
PURPOSE AND LOCATION
Oxygen Sensor I
The oxygen sensor I (G3/2), located in the exhaust system upstream of the catalytic converter, is used to provide more precise control of
air/fuel mixtures.
Oxygen Sensor II
The oxygen sensor II (G3/1), located in the exhaust system after the catalytic converter, is used to provide a monitoring signal to the diagnostic
module.
OPERATION
This system operates by measuring oxygen content in exhaust gases, as the amount of oxygen remaining in the exhaust gas is directly proportional
to the air/fuel ratio of mixtures entering the engine. The sensor, mounted in the exhaust stream, reacts to the oxygen remaining in the exhaust gases
and produces a variable voltage signal (0.4 - 1.0 VDC) depending upon the oxygen content.