Why does my 2006 Chevy cobalt shift choppy when it's an automatic?

It's almost like it's have trouble
shifting, like someone who doesn't
know how to drive a standard well.
The check engine light comes on and
tells me the problem is my MAP
sensor. Also, when I put my car in
neutral with the brake on, the shift
stick makes a clocking sound every
so often. Someone told me it could
be a neutral safety switch, but I really
want to figure it out exactly before I
bring it to the dealership to get it
fixed to know how much it's going to
be.