What hose is this?!? And how do I replace it? (2.4L)

Hey everyone,

I have a 1996 Grand Am with the 2.4L engine. I recently discovered a hose that needs to be replaced because it is cracked/torn near one of the ends. Problem is...I can't figure what the hose is/does!

The hose runs from the timing chain cover towards the front of the car for a few inches, then loops back around towards the engine and connects in there somewhere underneath the throttle body area (I haven't taken the parts out yet, so I can't see exactly where it connects).

Can somebody tell me:
1) What is this hose called? (as best as i can tell from my research I believe it's either a timing chain cover vent hose/tube or it's a crankcase ventilation hose or it's an oil/air separator hose...or maybe those are all the same thing?)
2) Is this a dealer-only part, or can I use any old hose? The big-name auto parts stores haven't been any help to me when I asked them about this.
3) Do I have to do anything special to replace this hose other than get to both the ends, unhook it, and hook up a new one? (i.e. relieve any type of pressure, disable any other parts first, etc.)
4) Can I patch the tear with some type of tape as a short-term emergency solution until I can get it replaced?

The car still runs with the hose in this condition, but I have had some driveability problems that I'm wondering if are related to the leak in those hose, as well as some recent oil-type odor off-and-on when driving. (There appears to be a small amount of an oily substance leaking from the tear in the hose.)

Thanks a ton for any advice you can give me!!!

Took them awhile, but the dealer finally figured out what the hose in question was. Please see my newest post for my question now about removing the intake manifold.