Lambda Sensors Catalogue

Lambda Sensors – "brought up-to-date"
Lambda Sensors – "the story so far ..."
Over recent years vehicle engine management technology has had to move on, in order to keep up with
changing EU Air Pollution Laws. As a consequence Lambda sensor technology has also moved on, which
means that the humble Universal Lambda sensor is not so universal any more.
With the introduction of ODB, EOBD II engine management systems and Direct Injection petrol engines, it
has become necessary to fit a more sophisticated Lambda sensors in the exhaust system. On post 01/00 engine
management systems there are two sensors fitted in the exhaust system, one located either side of the catalytic
converter. The first sensor in the exhaust system is the regulating Lambda sensor. This sensor is also known
as the pre cat sensor or the up stream sensor. The second sensor, which is located after the catalytic converter,
is the diagnostic sensor, also known as the post cat sensor or the down stream sensor.
Engine
ECU
Lucas Lambda Sensors
Pre Cat. Post Cat.
Sensor Sensor
Catalytic Converter
These sensors are the next generation of sensors and fall into two families. The first type is a Planar sensor
and the second type is a UEGO sensor, with 5 or 6 wires. These sensors were developed so the ECU can more
accurately meter the fuelling of the engine. These new generation Lambda sensors were first fitted from about
January 1996 until it was made compulsory in January 2000. Vehicle applications fitted with these types of
sensors need a dedicated, direct fit replacement sensor, with the same technical specification as the one
removed. Therefore universal Lambda sensors will not work properly on these types of engine management
systems and should never be fitted. So supplier beware*.
To this end, this Catalogue has been compiled to help you, the aftermarket supplier, establish which sensor
is required to do the job right and first time.
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