>>> P1163 No resetting by accelerometer, no periodic injector resetting.
After my work and resetting the fault memory the code that returns is the P1168. I have removed, cleaned and checked the fuel pressure regulator solenoid for free operation.
The P1163 appears to return if tow starting is attempted and the accelerator is pressed, I believe it relates to accelerator pedal signal implausible. <<<

Please slow down and read the DTC it is not talking about the APP sensor.

The P1168 code is telling a story as well, please re- read your last post from the outside and see what stares out at you.

The Delphi system is special in certain ways and it may well be worth sitting down with a coffee and having a read up on it.

Mark