1)keep driving it and pull codes again .

2) the info in both posts #2 & #3 are correct.

the cheaper and easier thing to do , first rule out any vacuum leaks:

A) EGR valve(exhaust man.) : on the forum some people have reported that an egr valve can sometimes stick open, when it does you will experience a vacuum leak which will cause a rough idle. from reading up on the forum, I believe that mercedes updated the design of the egr valve to fix this problem.

B) purge valve(has MOT stamped on it, location between fuse box an ABS unit)
they tend to get gunked-up. a gunked-up purge valve will not close completely, and that will also cause a vacuum leak. you dont have to buy a new one, just clean it yourself.

C) since you recently replaced the wiring harness ,go back and retrace your steps, make sure you did not disturb any vacuum lines.

if none of the above works, then inspect the ETA wire harness.