Why is the check engine light CEL on related to emissions in my Mercedes-Benz C-Class?

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Why is the check engine light CEL on related to emissions in my Mercedes-Benz C-Class?

The CEL often lights up due to emission-related problems such as a failing oxygen sensor, catalytic converter issues, o r EGR valve faults, signaling that the vehicle’s emission control system needs attention.

Talha Kyanii asked on 10 Oct 2025 17:00:18 pm

1 Answer

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Talha Kyanii - on 10 Oct 2025 17:01:24 pm

The CEL usually lights up when sensors like oxygen sensors detect abnormal emissions o r when components like the catalytic converter o r EGR valve malfunction.

Running a diagnostic scan with an OBD-II reader identifies the exact fault codes.

Replace faulty sensors o r repair emission control components as needed.

Ignoring CEL warnings can lead to worse emissions and potential damage to the engine o r exhaust system.