camshaft position sensor

I just bought a mustang on a used car lot in good condition. i notice over the last two weeks there is this screeching noise under the hood. it sounds like the belt. it makes the noise ever so often and sometimes makes the car kill. it killed one time and the check engine light came on so i went and had the auto store pull up the codes. it said my camshaft position sensor. i had them clear it and it has not come on since and that was 2 days ago but the car is still making that noise ever so often. is that the sensor causeing the belt to do that or is the belt causeing the sensor to send bad signals. any help would be great. please. :banghead: