Here is what one other owner had to do at a dealer, read through it and take it from there, and yes the pressure switch will cause this problem.
I have received the same error codes as all of you, t P0090 (Fuel Pressure Regulator 1 Control Circuit) and P0190 (Fuel Rail pressure sensor circuit malfunction). Same symptoms.
I've had the fuel pressure checked, valves, changed the spark plugs (by the dealership), software upgrade, cleaned the battery
terminals, ran heet through the engine about twice, and .... nothing.
The dealership couldn't figure it out either. Eventually they came to the conclusion that it was a corroded battery
cable, that they would graciously change for $800. ... so, I didn't do it, because I seriously doubt its the battery cables.
In the winter it had trouble starting as well, and would flood, I had to unplug the injectors sometimes to get it started.
I really can't think of anything else, i'll clean the throttle body
this weekend, and start running on premium to see if it makes a difference.
If the dealership can't figure it out, you know its a mystery. I'm starting to wonder if its a computer problem.