I will like to know while driving why does my.

THIS MAY NOT BE YOUR FIX

IT WILL COST YOU NOTHING TO TAKE IT OFF AND CLEAN THE SIDE THAT MATES TO THE ENGINE

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_idle-air-control-valve-bwd-intermotor_18481656-p?searchTerm=idle+air+control+valve#

I DON'T MEAN TO "DISASSEMBLE IT"

USE THROTTLE BODY CLEANER---MIGHT CLEAN THE HOLE IT GOES IN TOO

SEE MY EXPERIENCE IN THIS LINK

https://www.2carpros.com/questions/2006-ford-fiesta-engine

MINE DID NOT COST NEAR WHAT YOURS DOES---SHOULD THIS HELP YOU OUT, AND DECIDE TO GO WITH A NEW ONE, LET ME KNOW, BEFORE YOU GET ONE

THE MEDIC