So what does it mean when I push my truck hard enough for the tranny to go into limp mode and be stuck in 3rd gear, but not throw any codes? It's been happening alot recently, mainly when im trying to pass in 5th gear. When I first put the tune in it and this would happen, it would always throw a code.

Does the engine light come on?

Mine did the same thing about a month ago. I was trying to pass in 5th gear and it limped on me too. The check engine light came on and I had to crawl the rest of the way to work. When I got back in the truck to come home the light was still on but the truck ran ok. I checked it with my programmer when I got home and it showed some codes and I just deleted them out. The check engine light will go off on its own after about 3 or 4 cycles of the engine. It hasn't happened anymore yet but I am trying to be easy on it when I am in 5th.

Nope, I dont get any lights... Thats whats concerning me