[vprzebinda]

Quick question, this vacuum controlled device next to the EGR, attached to the turbo, what is it?:

 

[Stinkbutt]

I think it is emissions-related. I have a motor out of a 1985 300CD and it has something similar (same place, but looks a little different than yours). A while ago I found a thread either here or on peachparts that talked about what it does. . .and how to bypass it.

 

[Rmac58]

The attachment may help, the red X's are the delete items to get the egr out of the system.

 

[::matthew]

It's the ARV (air recirculation valve)