Mystery oil vent or line?

[gusthebus]

Having a hard time finding what this oil line is and if I need it. Never messed with it, stumbled upon it while I was redoing my gas lines. If anyone has any clue, let me know. Thanks !

 

[Spider4real]

That's a vent. It lets air in the tank as the oil goes down.

 

[mikidymac]

And Yes, you need it.