Mercedes E Klasse Hybrid NOx Sensor Issue

A faulty NOx sensor on a hybrid can trigger the check engine light and affect emissions. The exhaust smell suggests a potential leak worsening the problem. Given your mileage, it's not unexpected. Start by visually inspecting the sensor's wiring and connections for damage or corrosion. A malfunctioning NOx sensor can impact your car's air-fuel ratio. Have you checked the sensor's readings with an OBD scanner to confirm its output is within range?

I haven't checked the live data from the NOx sensor yet. Where is the NOx sensor located? Is it easily accessible, or hard to reach? If the readings are off, does that automatically mean the sensor is bad, or could it still be a wiring issue?

The NOx sensor's location varies but is usually found in the exhaust system, often downstream of the catalytic converter. Access can be restricted depending on your vehicle's configuration. Erroneous readings often point to a sensor malfunction, but always consider the wiring. Given the potential exhaust leak and the complexity of modern emission systems, I advise a professional diagnosis to ensure the correct repair. It could save you time and money.

I'll take it to a workshop. It was a faulty connector, just like I suspected. The bill was 95€ so I'm relieved it wasn't the sensor itself. Thanks for the guidance!