Oxygen Sensors for Efficient
and Lowest Emissions
The most popular method used by vehicle manufacturers to
control the exhaust emissions is the three-way catalyst.
This device converts the main pollutants in the exhaust gas
to less harmful gasses. However, the three-way catalyst only
works efficiently if the air-fuel ratio is within
very tight limits. This is the job of the where the oxygen sensor.
The oxygen sensor is situated in the exhaust pipe just
before the three-way catalyst. The central element of the
oxygen sensor is exposed to the exhaust gas.
The oxygen sensor continuously detects the oxygen content
in the exhaust gas. Its output signal is connected to the
ECU and changes to indicate a rich or lean fuel mixture.
Through its output signal, the sensor "informs"
the ECU if the vehicle is running rich or lean. The ECU uses
this information to decide whether it needs to increase or
decrease the fuel amount to achieve optimum air-fuel ratio.
This is referred to as closed loop control. By ensuring that
the air:fuel mixture is always correct both combustion and
catalyst efficiency are optimized.
1-Wire O2 Sensor & 4-Wire O2 Sensor