Lately whenever I get below half tank, usually around a 1/4 tank, my truck cranks over a lot until it starts and today I went half throttle or so and noticed I had hardly any power.

So watching my fuel rail pressure I noticed its only hitting 21000 psi at WOT.

Is this potentially a fuel pump problem?

No CEL, changed fuel filter 200 miles ago thinking it was possibly that, I'm just not sure.

Thank you in advance!