This is probably a dumb question, but here goes: If my truck has no o2 sensor input, will the computer just switch over to speed density mode? Otherwise I am wary to drive it with no o2 signal, especially for a long trip.

 

No, It wont switch into SD mode. It will throw a CEL and go into limp mode.
What O2 sensor are you not getting input to/from?

 

Bank 1 and 2 upstream sensors are not registering. The engine light is on, but so far the truck has not gone into limp mode. I have to drive about an hour or so to get home for thanksgiving next week, do you think the truck would be ok for the trip, or should I try and find a ride and wait to drive it until I have a new ecm?

 

Those sensors help control the air to fuel ratio the engine needs to run. Those being out will throw the AFR off and make the engine run rich or lean. If you have to drive the truck, I suggest not going WOT

 

It would be primarily highway driving. I'm just not wanting to run to lean or rich and cause more problems. Also, I thought WOT put the truck into open loop mode, not that I plan to run anywhere near that, just looking to clarify.