So have had my XF S 3.0D for 2 years and bar and alternator issue has be fine and have covered 50k since owning taking it to 103k. On way home Thursday and 20 miles into journey fairly fast 90-100mph and Red RP light came on, pulled over switched off engine and left for 10mins, checked oil and water (both fine) and restarted. Drove home and put code reader on and said it was Air mass correlation issue.
Have replaced both MAF sensors, cleared code. Took out for a run and after 5 mins taking it easy, started to accelerate on motorway and once it hit approx 3500 rpm went back to limo mode. Pulled over and same code had returned. Restarted to return home and Red DPF warning came on (never had any DPF warning previously)
Have also noticed a strange rushing air type noise (think from drivers side underload)
Anyone had this before and what was the outcome

 

Be careful as you may be risking serious damage - your car has failed to regen so the DPF needs cleaning properly.

Check your oil has NO SIGNS of diesel in the oil and DO NOT drive at all if it has because engine destruction is quite likely at that point.

 

Checked the oil and no change or smell of diesel. Guessing the engine must be running rich due to restricted performance which has in turn clogged up the dpf. Going to get dpf cleaned but need to get it bottom of the Red Restricted Performance. Any ideas what could be causing that?

 

Could be Turbo related or the dreaded cracked manifold issue , It is black plastic surrounds both sides of engine check it for cracks or splits

 

What was the codes ?

 

cannot remember the actual number off top of head but listed as Mass Air Flow Correlation Issue

 

Sorry I really tried to help now I got to back away good luck