Hpfp cp3 swap

[jordang78]

I'm pretty sure my fuel pumps on its way out car barley accelerates and am currently hearing a whine noise from the tank i got a code for fuel pressure sensor my question is if I change the cp3 to the cp4 do I need to change the fuel rail/injectors maybe that pressure sensor not sure but don't want to replace the whole fuel system

 

[JETaah]

Has it always done this since you've owned it?
Has the dieselgate fix been done on the car?

 

[wondermutt]

It's going to depend on the codes you've got. When mine went out the glow plug light started flashing and I got a low pressure code. If it is the HPFP, you'll find metal shavings pretty much scattered throughout the fuel system. If you remove the fuel metering valve on the HPFP and find metal shavings, the service manual says to replace the fuel sending unit, hpfp, common rail, fuel lines, all the injectors, aux pump, fuel filter, etc..

Hopefully, it's just the fuel sending unit acting up on you but IMO the two easiest places to look would be the fuel filter or fuel metering valve for metal shavings.