Vacuum line conundrum e46

[Iguana5500]

I just spent a couple of painful days replacing a starter (horrendous job which I can only match with rear wheel bearing replacement) in my 2000 328i M52TU. When I was done connecting everything I found a big vacuum line left over. I saw from another image that it might possibly be from under the intake straight in line behind the throttle body. I can disassemble again as necessary - but would like to know where this line (plugged with an orange plug in photo) is supposed to connect to.
https://ibb.co/kvMpkq

[bmwdirtracer]

Wow, Iguana, sorry you had such a problem with the starter. Next time, you should know that it's done from below, involves no unhooking hoses, and takes about an hour and a half.

That does not look like any vacuum line I've ever seen, because it has a metal crimp connector. It might be a purge (evap system) fitting, but even that's unlikely to have a big metal crimp. IF the next part AFTER the metal crimp is a plastic pipe, that's an evap system fitting, and the hose needs to be connected with another plastic pipe which goes to your purge valve, which lives underneath the front of the intake manifold, and will have two short rubber hoses and an electrical plug.

[MarcoZandrini]

It looks like an evap hose that’s been plugged.