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Check Lambda Sensor Functionality

Model: BMW Serie 7 E68, MK 4, E65, E67, E66 - Years: 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
Part: Engine

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The oxygen sensor, commonly known as the lambda sensor, detects the concentration of oxygen in the exhaust gases to maintain the air-fuel ratio (kg air/kg fuel) within the optimal efficiency range of the catalytic converter, known as "lambda 1". The sensor then transmits this information via an electrical signal to the engine control unit, which regulates the intake of fuel and air into the combustion chamber; it is clear that a malfunction of this sensor will negatively impact fuel consumption and engine efficiency.

When the sensor fails, the check engine light activates, storing the corresponding fault code, but it is important not to focus solely on reading the fault codes; you should verify the malfunction by checking the parameters: comparing the voltage value of the two sensors shows that the one related to the second bank is out of range.


Updated on 19 February 2026 by ScegliAuto


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