Check the Mass air flow sensors for debris or if wet. I've heard a interesting situation that putting on a higher flowing oil filter can cause something weird to go on with the oil sensor. Gregs truck died because of that Canister Purge Valve. There lots of crazy cenarios that can cause fluke instances that'll make the truck die. Now for the instances that the truck dies on a hill climb makes total sense to me. Depending on where the fuel pump is placed in the fuel tank, it can run out of fuel. The fact that our trucks are wet sump oil systems instead of dry sump systems, you can starve the engine of oil therefore triggering the oil pressure light. Having a external fuel pump instead of in tank fuel pumps could help the starvation of fuel to the engine as well. If you're slamming on the brake pedal therefore causing the fuel to slosh to the front of the tank starving the pump of fuel. Just saying.