camshaft sensor and evap monitors are on but no check engine light. what could be causing this issue?

 

I assume you mean you plugged a an OBD2 scan tool in, and it's saying the emissions system is not ready, or something similar depending on the model.
Did you recently disconnect the battery? When the battery is disconnected, and the pcm is reset, it has to go through a set number of cycles before it will show whether or not the emissions system is in working order. Basically, drive the truck more and check again later.