Go to an auto parts store and buy the Haynes or Chilton's manual for the contour. The tensioner is not that hard to change your self. You can visually inspect it by pulling off the passenger's side front wheel and then the plastic slpash guard. Simply follow the serp belt down to the lower left of the assembly. There you will find the tensioner pulley.
The Haynes manual will walk you through what you need to do. You don't even need a lot of tools. Its more time consuming than dificult. You can do it.
