Oxygen sensor
Measures exhaust oxygen to support mixture or catalyst monitoring.
Threaded into the exhaust before or after treatment hardware.
Heated sensing elements produce signals interpreted differently for control and monitoring positions.
A taste tester reporting how combustion is going.
Mixture or sensor faults can arise from wiring, exhaust leaks and genuine fueling problems.
Condition, contamination, operating pattern and the underlying engine matter more than a universal age limit.
Sensors and joints differ greatly from complete after-treatment assemblies. First repair the cause of contamination or abnormal combustion.
Upstream and downstream BMW oxygen sensors can have different functions and specifications.
BMW combustion models; petrol and diesel after-treatment components differ by engine and market.