What causes the Mercedes E-Class to have faulty oxygen sensor readings leading to poor fuel economy in Pakistan?

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What causes the Mercedes E-Class to have faulty oxygen sensor readings leading to poor fuel economy in Pakistan?

Lately, my Mercedes-Benz E-Class has been consuming more fuel than usual, and the check engine light indicates an oxygen sensor issue. Considering the fuel quality and road conditions in Pakistan, what are the common reasons for oxygen sensor failure? How does this affect engine performance and emissions?

Talha Kyanii asked on 11 Oct 2025 14:12:20 pm

1 Answer

11 views |

Gari Master - on 11 Oct 2025 14:13:59 pm

Oxygen sensor problems in Pakistan are commonly caused by:

Poor fuel quality: Low-grade o r adulterated fuel leads to deposits that can foul oxygen sensors.

Exhaust leaks: Leaks near the sensor can cause inaccurate readings.

Sensor aging: Oxygen sensors have a limited lifespan, and prolonged exposure to heat and contaminants reduces their efficiency.

Engine misfires o r rich/lean mixtures: These conditions damage the sensor over time.

A faulty oxygen sensor causes the engine control unit ECU to miscalculate the air-fuel mixture, resulting in poor fuel economy, increased emissions, and rough engine performance. Replacing the sensor with a genuine part is crucial.