Sounds about right from some dealerships, I had a dealership tell me that everything I took my car in for was not covered under warranty but then when the warranty was up suddenly it would have been covered if i brought it in then. sometimes i dont get it.Well I got an update from the toyota dealership. Supposedly when it went over to the Nissan dealership, the check engine light was not on, no codes were coming up, and everything is fine... They have been driving it and absolutely nothing is wrong they say. So the thud, check engine light on, and not being able to accelerate just disappeared and all is good now? Seems rather shady to me. Not to sure what else to do rather than to get the truck back and drive it myself for a while.
good luck, there is nothing worse than having to deal with that stuff on a trip