Thanks for the link to the buttons.
I haven't checked fuel pressure. I'll get a gauge on it and see what it reads.
I do go through the diagnostic process in the FSM for the MAP and it tested fine. All wiring had proper continuity and voltage. The only thing I can think of was the connector for the MAP was missing the grey rubber seal around the end that goes into the sensor. Without the seal, it fit loose in the connector. Hopefully that's what the intermittent problem was.