What brand?

Try this:

Grab a friend, reset the PCM again. With the air filter off, look down the TB, and have your friend turn the ignition on, (not start, just on.) Watch the IAC port, the pintle should completely close, then back off a bit. Does it?

 

The iac? Not sure what brand. It was purchased at napa.

 

Computer reset. Key to on the iac did close all the way and did back off. More then a little bit but it did back off.

 

Might also be a computer issue, as mentioned in the video below about half way through:

 

IAC and it's control circuits are working then. Could try cleaning the connectors at the IAC, and at the PCM. (I didn't watch the video..... gonna go to bed real soon.)

 

Thanks for the help. I'll try cleaning all of them.

 

What condition is the battery? A weak battery will cause idle issues. (First hand experience) Had a battery that would start the truck fine but tested a tad on the weak side. It would not want to idle on it's own. Replace it with a new battery and idled perfect. I have heard of this issue that others have had also.

 

The battery is new. The o2 sensor seems to have helped. It is idling better most of the time but it still dies at least once or twice a day when I drive it. I was hoping it was just needing to relearn so I'm giving it a little time.

 

I have heard of people replacing these (with new parts) three times to find one that works correctly. Not sure if this is your case or not. If it continues i would get an oem iac. How many miles are on the throttle body? I have seen the throttle shaft wear the body and cause a vacuum leak causing idle issues.

 

This is my second new iac but it makes sense to me that the iac may not be the issue since it doesn't have any problems til it warms up and the computer uses the o2 sensor. I am on my third o2 sensor but now I know not to buy a Bosch. I don't have any vacuum leaks. The hissing sound is coming from the iac and the fact that it is opening up and leaning the fuel out til it dies.