I know it’s been talked through a billion times. Figured I’d give it one last chance before I bring the car in to the dealer. I changed the manifold myself , took an hour and a half. Yes I did it correct, yes all the vacuume lines are correct, yes all the electrical connections are connected , yes the new part is good with new sensors and such. Yes the gaskets are installed correctly and lastly yes, I consider myself very capable as I’v worked on cars since my first car in the early 90’s. This job was actually fairly simple in my opinion. The car idles completely fine, runs as if new, never showed a symptom. The old
one had a center broken actuator arm. I’m thinking....

bad connector/broken wire
bad computer
bad brand new part/sensor

I clear the code and it’s back within a few miles. Most likely will have to go to dealer if I can’t figure it out.

Any last minuet thoughts guys.

 

im having same issue on my w204 C350, did you ever get it sorted out? Also, mine doesn’t idle good though even after swapping out. But, I had help from Mercedes mechanic (friend) while we repaired I’m sure we did everything right as you also did.