Cayenne Turbo No Start, P0192, P1031, P1024

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2011 Cayenne Turbo, 85K miles, 3/4 tank fuel

Car started normally 4 times/ran flawlessly for about 45 minutes driving during a 2 hour period. After the last 30 minute rest, the car would crank but not start, then intermittently start after a long crank and subsequently stall. An engine reduced power warning would display and continuous check engine light. Eventually engine would not start or not run for longer than a few seconds.

I read/reset codes with the following results:

P0192 Fuel Rail Pressure Sensor Circuit Low Input
reset and did not return

P1031 Fuel high pressure sensor stuck at start
unable to reset

P1024 Fuel high pressure too high after engine off
reset and did not return

Car still unable to start/maintain idle.

After about 1 hour, I returned to the car, reset codes (this time all cleared)--the car started and ran flawlessly!

Anybody else have something like this happen? Should I replace the High Pressure Sensor or order and keep one around--are these prone to failure? I'm having a hard time finding a diagram with the HP Sensor for the Turbo engines, is it located under the intake manifold like the non-turbos? If so, is intake manifold removal on the turbo very difficult? Any other things I should be considering?