A while back, I got a "low idle" code? According to the guys at Autozone. They cleared it and said it was probably a false code. Thats when I had straight pipes. Now I have true dual flowmaster 40's. The first night after i put them in, it was cold, and I floored it on the way home to see how it sounded. I parked it and turned it off, and thats when what looked like smoke began to slowly seep out. It smelled like something was burning also. It only did that a couple times, only in the cold though. But to this day, I can still smell the burning smell out the exhaust sometimes. Now for the noticeable problem: When I turn my air conditioning on, the rpms will radically go up and down in a couple second intervals. Is it the IAC??? Sorry for the long story, guys.

 

Bump...

 

There's a proceedure that's described in your owners manual that tells you how to get the PCM to "learn" the idle. It requires you to disconnect the battery, start the truck and drive a certain number of minutes, etc.) I do not have my owners manual handy, so you'll need to read up on it. If you don't have one, download it from here:

https://www.fleet.ford.com/maintenan...ls/default.asp

 

Thanks man, I didn't even think to look at the owner's manual.