Mercedes S Klasse Diesel Low Exhaust Pressure

My 2019 Mercedes S Klasse Diesel is showing a warning light and has reduced engine power. There's also smoke during acceleration and a strange smell from the exhaust. My tool says the diesel particulate filter exhaust pressure is too low. Could it be a defective exhaust back pressure sensor? Has anyone else seen this?

4 comment(s)

Sounds familiar. I had something similar happen with my old Vauxhall Astra diesel. Reduced power and a weird smell. Could be the pressure sensor like you suspect. Have you checked the wiring to the sensor? Might just be a loose connection.

I haven't checked the wiring yet, good idea. Where is the sensor usually located? Is it easy to get to, or do I need to remove other parts?

On my Astra, it was near the particulate filter itself, fairly easy to spot. Should be a small sensor with a wire going to it. But honestly, with those symptoms, especially the smoke, it might be best to get it checked by someone who knows these emission control systems well.

I took it to a workshop as suggested. The exhaust back pressure sensor was defective. The repair, including the sensor, cost 245€. The car is now running great, and the issues are gone.

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