2005 (L320) RR Sport TDV6 - Revs Fluctuating/judder, rough idle & Limp Mode

Hoping someone can help, I own a 2005 l320 TDV6. Had a fuel issue not long ago and diagnosed it as LPFP. Changed it and got the car running again.



Since then there has been a juddering under acceleration. Mostly noticeable up hill. It’s also audible. It is also still there when in park. It’s as if there is a misfire



The car will sometimes go into limp mode if you try and floor it, it starts absolutely fine



I have scanned it and got these codes

U0401(94)

P2288(00)

P2292(00)

And also P140A(00) and P0405(00) however EGRS are blanked



Can anyone shed any light? Or point me in the right direction for diagnosing

Did you replace the fuel filter? if so, did you connect the four pipes correctly?
What was the reason you replaced the low pressure fuel pump?
Those two 'P' codes can be indicative of the PCV on the HPFP sticking, unfortunately the only fix is a replacement HPFP...
If you haven't changed the fuel filter, change it as a first step. If you have, check the pipes are in the correct position on the filter.

Yes replaced the fuel filter when had original issue that turned out to be the LPFP.

I have since changed it again to try eliminating that, I’m almost certain there in the correct position.

Is there any way of testing it is the PCV. Also what is the PCV?

Cheers mate

Pressure Control Valve - it's on the side of the HPFP. The two relevant 'P' codes are for rail pressure fluctuating & rail pressure high which are caused by a defective PCV or occasionally by the fuel filter being mis-connected. I'd check the connections as a first step, then the wiring to the PCV (although as there are no relevant DTC's indicating open or circuit high/low it's probably OK) and the wiring & pin grip on the fuel rail pressure sensor.
Have you cleared down the DTC's after changing the fuel pump module? (LPFP) these codes can also be caused by a defective LPFP.
There's no way of testing the PCV itself as it's not a servicable item, sometimes it sticks due to the HPFP vanes breaking up, which, if it is in your case, will not be great news for the fuel injectors...