Tom P
I'm Awesome
These trucks don't need fuel pressure sensors. Even if they knew, they wouldn't be able to do anything about it. The injector flow values are based on fuel pressure, so all you really need to do is hook up a gauge to know everything is OK. You can rent them from the parts stores.
I did rent a gauge from a parts store. Only one in my town does. I got a maximum of 30psi (according to the gauge) out of a running engine. According to the GM shop manual it shouldn't be running with anything less than 44.