Application Guide

ECU
Catalytic Converter
Primary
Oxygen
Sensor
Fuel Injector
Spark Plug
MAF Sensor
The worldwide leader in oxygen sensor technology
Bosch invented the automotive oxygen sensor in 1976, and
has been at the forefront of the technology ever since. Bosch
works closely vehicle manufacturers worldwide to create the
most efficient and reliable systems to keep your vehicle
running efficiently. Our experience with vehicle manufactures
means we have the capability to produce parts that meet
vehicle specifications.
What is an oxygen sensor?
An oxygen sensor detects the amount of oxygen in a vehicle’s
exhaust system and sends a signal to the Engine Control Unit
(ECU), which adjusts the amount of fuel delivered to the
combustion chamber.
Too much oxygen in the exhaust or too little fuel being fed to
the engine indicates a lean mixture, which can cause
performance problems. Too little oxygen or too much fuel in
the exhaust indicates a rich mixture, which results in lower
MPG and excess emissions. Either condition can shorten the
life of the catalytic converter, which removes harmful
pollutants from the exhaust.
Almost all gasoline powered vehicles since 1986 have at least
one oxygen sensor, and vehicles manufactured since 1996 will
have at least two. There is one sensor that is located before the
catalytic converter to communicate with the EMC to let the car
know if it needs to use more or less fuel. A second sensor is
located after the catalytic converter to make sure that the
catalytic converter is working properly.
Engine Control Unit
Receives information from the primary oxygen
sensor regarding the amount of contaminants
in the combustion system.
Primary Oxygen Sensor
Positioned before the catalytic converter, these sensors send
engine air-fuel reference signals to the ECU so that fuel delivery is
adjusted to optimal working conditions.
Secondary Oxygen Sensor
The secondary oxygen sensor is used to monitor the efficiency
of the catalytic converter and sends signals regarding how well
the vehicles catalytic converter is working.
Mass Air Flow Sensors (MAF)
MAF Sensors record the exact air-fuel ratio entering the
combustion engine. The sensor then transmits this information
electrical signal to the ECU.
Catalytic Converter
Removes contaminants from the combustions system. Without
the correct air-fuel mixture provided by the ECM, the converter
cannot eliminate harmful pollutants from the exhaust gases.
Combustions Chamber
The fuel injector sprays fuel into the combustions chamber.
Fuel is then projected into the cylinder, removing all of the
oxygen and igniting the the spark plug.
Fuel Injector
Based on a signal received from the ECM, the right amount of
fuel is delivered to the combustion chamber resulting in the
optimal air-fuel mixture in the engine.
Spark Plug
The spark plug is designed to produce the spark
that ignites the air-fuel mixture in the combustion
chamber of gasoline engines.
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Secondary
Oxygen
Sensor
Combustions Chamber
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Bosch Oxygen Sensors