I noticed there is a new part number for the IAC valve.
Old part number: XS2Z9F715BA
New part number: XS2Z9F715BC
Is is this an improved part?
The site where I found this is
http://www.newfordparts.com and go to Ford Parts. Just type in XS2Z9F715BA and it will give you a price for the old part but also tell you there is a new part number, XS2Z9F715BC. The new part is more expensive.