Does anyone know of a OBD II that will read the low side fuel pressure. Mine seems to only read the high side at the fuel rail. I have gotten a P15DF code and believe it is the sensor but my reader won't give me the low side.
I can't say I know of any OBD2 reader besides the BMW specific ones that can read the low pressure sensor. For the code you have is talking about pressure in the high pressure fuel system being to low on a cold start. That will normally point to a injector leaking. Have you checked the index of your injectors to make sure they are 11 or greater?