If you leave that front hose disconected, its going to allow DIRTY AIR, into the top end of your engine, and then allow all that extra air into the intake manifold causing him to run lean?(more then likely it will just piss off the computer)
Im sorry to say this, you might just have a really hi idle vacuum, I would assume there are things you can do to bring that down which in turn would bring down your crank case vacuum.
For me, I would like to thank you for the reason that I never thought about my dipstick tube SUCKING stuff in. come the first I think I may be getting a new dipstick
