No this code isn't back. But it does still have a rough cold start idle. There is a vestigial brake booster plug that is an overly complicated design that the non-SBC cars use that can leak. Putting some info here so I don't lose it.
https://mbworld.org/forums/w211-amg/686 ... g-air.html
https://stumptownbenz.com/simple-plug-f ... cuum-port/