I have a p1504 code on my excursion v-10 I research the code it says faulty IAC I order one from advance auto and install it runs for a day then starts dying again I go to advance and they swap out the part I install the 2nd new iac and two days later the same thing I have to two foot her at stop lights. Can someone tell me do I need to use motor craft part advance $56 ford parts $146. I am open to all ideas thanks guys

 

You likely have a vacuum leak which is making it impossible for the IAC to control the idle.

Did you check for any leaks first?

 

Went through two advance ones before I broke down and went to the Ford dealer. I had the moaning sound at stop lights as well. Buy the dealer part and the upgraded tube that goes to it. Haven't had a problem since.