It's a vortec 454. I've replaced iacv maf tps map and all intake gaskets. There are no vacuum leaks. I put the new iacv on and it idles down so low it would die. Replaced the iacv again and it idles high again (around 2500 rpms) I went back to the iacv that makes it idle low and manually adjusted the throttle so it will run. It runs fine like this but I know it isnt right. As far a codes go it showed the map then the maf. Now the only code I get is "iacv unresponsive" which is because the one I am using now is stuck but it is the one that works. Does anybody have any suggestions? Thank you.

 

Did you check for any plenum air intake leaks?

 

I did and replaced to gaskets anyway. Checked all the upper intake for cracks and cleaned it as well.

 

I AC might not get proper voltage or a wiring issue.