4.7 Idle Air Control Valve or Throttle position sensor

My 2000 4.7 is having similar idling & stalling issues at cold start as stated in this forum. The battery is new, along with the usual tune-up items. Sounds like the Idle Air Control Valve or Throttle position sensor could be the problem based on my reading. How do I test or clean these modules? Note that there are NO error codes recorded, and scanning does not show anything. The Durango seems to run & idle fine after it reaches operating temp. Notice more problems in damp or wet weather. Thanks in advance for your help.