So it started off with me Evap issue like replacing the vapor canister vent then replacing the I.A.C valve and after replacing the I.A.C valve I started having issues when when in idle the car will start to idle hunt. Rpm’s will shoot up to 1500 then will immediately drop back to 1000 and it will keep doing that repeatedly I also pulled up code as to see what could be the issue but it keep telling me that it is a p0505 code which is the idle air control system which makes no sense to me because before change the idle air control valve it did not have that issue so now that’s where I’m kinda stuck and can’t figure out what the issue could be.

 

I know this is a broken record...........but did you check the PCV valve on the top of the valve cover to make sure that the check ball is still there? Just lift it off the cover and put your finger over the orifice to see if that will stop the idle from surging.