

What do these lines do? They terminate to open air!
Where can I go to learn the details of what this thing does? A couple of its ports are tied together before going to a mini air filter, and then through the firewall. The lines Y off before the filter and the other part of the Y comes back to this device, but has nowhere to hook up to! I'm so confused. What the heck does this thing even do?
1985 300D OM617a Turbo Federal spec (I'm told)