Why are Lambda Sensors fitted?
The most popular method used by vehicle manufacturers
to reduce vehicle emissions is the three-way catalyst.
This device converts the main pollutants in the
exhaust gas to less harmful gases.
However
the three-way catalyst only works efficiently if
the air-fuel ratio can be kept within very tight
limits. This is where the lambda sensor comes in.
The
lambda sensor continuously detects oxygen in the
exhaust gas. As the output from the sensor changes,
the ECU changes the quantity of fuel injected which
alters the mixture strength. This is known as closed-loop
control and ensures that the mixture strength is
always correct enabling optimum catalyst efficiency.
