Mercedes GLK diesel exhaust sensor problem

I had a similar issue with my Mercedes GLK, but I don't recall the build year The symptoms you describe align with a malfunctioning exhaust back pressure sensor The inability of the DPF to regenerate is a common consequence, as the engine control unit relies on accurate back pressure readings for emission control Vehicle emissions exceeding normal levels is also expected Did you perform any vehicle diagnostics prior to observing these issues Incorrect readings from the exhaust sensor can indeed trigger these problems

Thanks I did a quick scan with a generic OBD reader, which flagged an 'exhaust sensor circuit malfunction' error I also noticed the engine seems a bit sluggish Is there anything else I should check before replacing the exhaust sensor?

The error code you retrieved using vehicle diagnostics confirms the issue Considering the symptoms—smoke, DPF regeneration failure, and the error code—it is highly probable that the exhaust sensor is indeed defective Before initiating the replacement, inspect the wiring and connectors associated with the exhaust sensor Corrosion or damage to the wiring can cause similar symptoms However, given your description, replacing the sensor is the most likely solution I suggest you visit a workshop to get it replaced

I checked the wiring as you suggested, but everything seemed fine I replaced the exhaust sensor Problem solved The warning light's gone, no more smoke, and the DPF is regenerating again Emission control is back to normal Thanks again for confirming my suspicions