chirping noise

Assuming that you have not replaced any parts ie: P/S Pump, Generator etc. Remove the belt, Clean the grooves in all of the pulleys. Replace the Belt tensioner. If any pulleys with the exception of the belt tensioner have been removed, they may have to be realigned with a special laser tool. FYI, never use any belt dressing on a serpentine (Multigrooved belt) This will only make it worse.