dies at stop signs on 2000 Ford Contour

I just bought a used 2000 svt contour and it stalls somtimes at stop signs what could be the reason?Ijust changed plugs!!

Asked by for the 2000 Ford Contour
2 answers
Try focusing on the idle valve, when they get old/dirty this problem occurs. You can try cleaning it or it may need to be replaced.
(iac) valve