This vehicle came in to us with a check engine light complaint, had code P12A2 fuel rail pressure high,
we found the in tank pumps were weak, replaced pumps, regulator, and filter.
We drove the car and it set the light/code again. We then replaced the fuel pressure sensor, same problem.
We then replaced the high pressure fuel pump and now it takes longer to set the fault but it still sets the fault.
The car runs fine under load, intermittently it has a very slightly rough idle.
We have smoke tested the intake, no leaks found. We checked the crankcase for excessive vacuum, seems normal.
We are not sure why it is setting that code or what the criteria for setting that code is.
Most of our research shows that people have fixed this problem in the past with either in tank pumps or high pressure pumps or
vacuum leaks or failed crankcase vent valves built into valves covers.
We are not sure where to go from here.