Fuel pressure CM 871

[Mrkentee]

A year ago I got fuel pressure differential code 2372 in hot weather in a long pull. It would go away after key turn. Checked fuel pressure which was borderline and replaced pump. It had over a million miles on it. The problem didn’t return until lately, again in hot weather in a pull.
Lately I’ve gotten 2372 pressure differential, and 482, 2215 low fuel pressure. A few of the times it feels like the power is cut back some all of a sudden. Otherwise the truck runs fine. Any ideas?