What these two vac lines for? the one on the right (facing rear) has been long gone. Do I need to plug the hole? I know that the answer is here somewhere. I looked and looked. I just need it explained in very simple English what these two lines do. And if they are necessary.

 

Ok so I figured out that the left hose goes to the fuel pressure reg. That one is in good shape. I want to just plug the hole on the right. EGR and PUrge have long been gone. So can I just plug the hole?

 

Will bump for you

 

Short answer is YES. Long answer is that, unless you want that hole sucking in umetered/unmeasured air every time you open the throttle (because it's a ported vacuum source in front of the throttle plate), you will want to plug it.

And for future reference, those 2 ports are reversed on the 3.1 TB...