I've only seen this hose on n18s and even then not everyone I've seen has it , You by chance know what this hose goes to and if it can be plugged or does ot gotta be plumbed onto the intake ?
I'm wondering if I can just plug the line or if I need to plumb it into my intake because I don't want a cel or cause an issue..
Any help is always a big help .

 

That hose is part of the crankcase ventilation system. It goes down to a port below the intake manifold. You won't gain anything by deleting it.

Here:
https://www.realoem.com/bmw/enUS/sho...diagId=11_4587

 

Well I will leave it the way it is because I don't want excessive crankcase pressure, especially since im running a big turbo. I will just install a boost tap into my intake hose inorder to retain that's lines purpose...
thx you !