stalling problem

Hi evryone,
I searched this forum for this problem but didn't quite find this specific problem. My son has a 99 Contour that is automatic with the four cylinder. It runs fine but sometime stalls when he slows down with the brakes. Some days are worse than others. Is there a deceleration valve I need to replace. I don't have any experience working on Contours so any thoughts would be appreciated.

i have a 95b contour if ur car is making a loud noise and then die it could be ur idel sensor