CELs will go out on their own but sometimes it takes a while to do so. You can clear them with a scanner (e.g. VAG-Com) or by disconnecting the battery for a little while. Obviously disconnecting the battery will also screw with your radio and other stuff, though.

 

on the topic of vacuum lines, does anyone know what that little blue thing does on top of the engine. the thing that acts like a one way vacuum (diode). i dont know the exact name, but what happens when you take it out of the system, as i ran without it for a few days after it broke and replaced it with a new. the system is now saying "system running too rich" even though i have replaced it.