So my truck runs fine most of the time, but lately its started to die off when I've got the clutch in and I'm coasting downhill.

It doesn't do it every time, but 3-4 times a tank it'll cut off. Fortunately I've noticed right away each time and started it back up. Power steering/brakes cut out with the engine - definitely a recipe for disaster. Doesn't seem to matter what speed I'm at or how much throttle it had before the coast.

Any ideas?

 

Either throttle position sensor or splice located under the distribution box under the hood.There's a write up about the splice in the FAQ section.