2000 Chevy Cavalier idle speed

Can my idle speed be adjusted on my 2000 cavalier? It seems to idle a little slow. I heard some mild annoying noise under the hood, especially when in gear while idling. I noticed it was the belt slapping a little, and would smooth out if I picked up the idle a little. None of the pulleys were wobbling. Would a new tensioner help, even though the tension seems good.
Thanks, J