Vacuum hose

I am having problems again with my 97 GT. The RPMs drop and go up and it will run rough especially at first. The scan says this could be one problem. I picked up a MAF sensor at a junkyard and the code comes on when the MAF is disconnected or connected. I also feel like I am not having acceleration or stopping power as I did before, one mechanic a while back said it could be a loose vacuum hose connection, any idea where this would be? Thanks in advance for the advice or help.

That sucks. I had a cracked hose and it kept shooting off my check engine light saying my EGR valve was bad. It was the plastic hose right under the S/C'er pulley. I'd check any plastic hoses first because they're cheap pieces of crap that crack easily.

If stopping power decreased, check that huge vacuum hose that goes from the UIM to the brak booster.