Why does my Mercedes-Benz C-Class fail the emissions test in Pakistan? Detail:

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Why does my Mercedes-Benz C-Class fail the emissions test in Pakistan? Detail:

Many owners face emissions test failures due to elevated exhaust pollutants like CO, HC, o r NOx, which could be caused by engine tuning issues, faulty sensors, o r malfunctioning emission control systems.

Talha Kyanii asked on 10 Oct 2025 16:59:40 pm

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Talha Kyanii - on 10 Oct 2025 17:00:57 pm

Common causes include faulty oxygen sensors, dirty air filters, o r malfunctioning EGR Exhaust Gas Recirculation valves that increase pollutant levels.

Engine tuning issues such as incorrect fuel-air mixture o r ignition timing can also cause high emissions.

Regular maintenance like changing air filters, spark plugs, and timely servicing helps reduce emissions.

Using quality fuel and additives that clean the fuel system can improve emission test results.

Have a diagnostic scan done at authorized service centers to identify and fix emission-related fault codes.