Throttle body relearn?

Replaced the throttle body with new TPS and gas pedal with sensor, I did the throttle relearn with my scanner and it worked after the third time. It went right back into limp mode, so I don't again. And again. Again. So, after the 7473rd time it took and I drove for about 45 minutes and it ran okay, it was running a little rough but that's normal while it learns. I stop, check things out and kill the engine. I start up to leave, limp mode and that was a week ago.
I bought the GM professional shop manual, 11800 pages worth and I guess the truck has to be within certain parameters or the relearn won't work. I can clear the codes I need to clear, but they immediately come right back so I can't do the relearn.

I've hit my wall, where do I go from here? I have a great scanner with plenty of capability but i'm lost.
any ideas?
thank you!
Jeremy k.