Posting here as this section gets most views, and we share the same engine.
2013 ML63 48k miles
History: Truck ran amazing tuned and untuned. E50 Eurocharged Tuned By Jerry
Had CEL for misfire, took in for service and noticed that #7 plug had an electrode that was closed shut. Did leak down and compression test came back normal. Replaced all plugs and it ran fine again but then started to have a slight miss/vibration at idle but would throw no codes. Power was down. I replaced all ignition coils with updated part #s, no change. Then noticed I had oil in camshaft sensor, replaced all sensors and it ran great for a bit. Miss came back no codes and down on power. I noticed I had slight oil on ECU blades oil on cam sensors and on 4 of the fuel injector harness connections. Cleaned up all with contact cleaner and let sit for a few days. Truck runs good but its still "off" but wont throw codes. I think the entire engine harness is fouled with oil and needs to be replaced. I cannot get to the front two 02 sensors to see if they are fouled.
Engine has slight rough idle that comes and goes. Power is down, I get a delay in boost onset in-between shifts. Im lost, I just ordered all new cam solenoids. The only thing left is to replace the entire engine wiring harness. Has anyone encountered this issue to this extent? Any help is appreciated.

 

This was my issue. running bad, had oil in harness and it took out driver's front O2 sensor, plug was full of oil, also from leaky cam sensors.

Good luck

 

thx man, as crazy as it sounds I HOPE that's the only issue, it would be relieving.

 

What was your outcome?