2003 DEVILLE STALLING PROBLEMS

I have a 2003 Base DEVILLE and it has been stalling randomly.  There has never been a Check Engine light on.  I ran the ODBII anyway and there are no codes stored.  The stalling happens when the vehicle is at idle, usually at a stop light, stop sign, or when backing out of a parking spot and then switching into drive.  When I try to restart the vehicle after stalling, it just cranks and cranks for about 20 seconds until it starts.  Otherwise, the vehicle drives perfectly and starts regularly without fail.  My thoughts were originally to replace the fuel filter....  After reading some posts, it looks like it might be the crankshaft position sensors???  Would the cranshaft position sensors throw off a code and turn on the Check Engine Light?  I appreciate any feedback!!! 

Check grounds, Fuel pressure, connector at fuel pump ( under access plate in trunk), Make sure throttle plate isn't carboned up. If everything is ok, then crank sensors are a good choice to try.