I have shared this in the "What have you done to your Merc today" thread, but I believe it may also be beneficial to put it here. I will provide any updates or solutions in due time.
E350 CDi has the updated OM642 engine. EML activated en route to work on Friday. Successfully transported me there and back home, fortunately, without any apparent symptoms. Operated regularly, smoothly, without any knocks, responded well under moderate load, and emitted no smoke (did not attempt full acceleration).
I presented it to my independent entity first thing this morning. It began adequately but exhibited hesitance in shifting gears. The vehicle shifts down automatically at approximately 3,000 RPM, while manual paddle shifting occurs at 2,500 RPM, and it does not exceed 5th gear with the 7G-Tronic gearbox. Otherwise, it seems satisfactory.
I suspected the NOx sensor, but the mechanic disagreed, considering the gearbox issues observed this morning.
I anticipate a call.