This may not be what you want to hear, but there's a lot of history on the "air pump' in the archives.
Key in -> air pump
then click "titles only"
Look for posts from Arthur Dalton, someguyfrommaryland, M.B.DOC; stevebfl. I believe there's one started by Engatwork as well. If you dig hard enough, you may be able to figure out how to fake out the system so that you don't drive a CEL if you disconnect it. Of course this is illegal and I personally would never dream of doing such a thing.
M.B.DOCs comments in this thread state the devices basic purpose:
What's an Air Injection Pump designed for?