All of a a sudden my contour is acting strange. When i'm driving in gear and then throw it in neutral, while still moving, the idle falls real slow and then once it drops to 1000 rpms it just falls all the way to 0 and stalls while still moving. I'm going to clean my IAC 1st and then the Mass air sendor but how do i check for vacuum leaks? what else should i check? the CEL light is on but i have yet to check it. However, the CEL was on before any of these idle problems ever happend. thanks