Perhaps the park/neutral return signal wire from the transmission range switch on the transmission is intermittently grounding out enough to drop the voltage on the supply side of that circuit, which is T'eed into the ign power wire and the MAF power wire.
Looking at the wiring diagram, off the power hold relay, the hot wire goes to "splice 54"(right side engine compartment) and from that splice it goes to:
-ign power (two separate wires to the PCM, terminals #71 & #97)
-trans range selector switch
-MAF sensor power wire
-overdrive cancel switch