RE: Rough Idle 5.9
All of these frickin trucks idle poorly. I have taken mine to different dealerships, when I bought it new, and was told that "it was normal nothing is wrong". Now at 56k and a new fastman tb, new iac, tps, and map sensor (I replaced all of them at the same time I put on the new tb, just to see if it helped), the idle is still rough. But the tb did improve performance.
I run premium and have since new which is the only way to keep the knocking/pinging from happening.
I don't think you'll be able to correct that idle problem.