Can anyone tell me what the tube and valve in the front of the main picture at the link is? Goes into the cylinder head and comes through the intake manifold and connects back behind the throttle body on the intake manifold.

Intake Manifold C220 M111 Mercedes 111 961 | eBay

Probably EGR with the valve diaphragm on the right lower.

Thanks. I tried that and it led me to what I think is the part. "EGR shutoff valve."