I have identified an engine management code DPO171 after connecting a scan tool to my 2008 XF 4.2 V8 petrol after the Engine Management warning light was illuminated on the dash .
The description read -- SYSTEM TOO LEAN ON BANK 1.
The RACV roadside assist mechanic said he suspects the fuel filter is partly blocked or there is an air/vacuum problem .
I have recently run the petrol tank very low down to almost empty a couple of times and suspect I may have picked up sediment which may have caused the blocking in the fuel filter .
I would appreciate hearing from anyone who may have experienced this same problem .
The car runs perfectly and I will change the fuel filter but if that doesn't fix the problem I would like to know what to do next .

 

Also
DPO -> P0

(drop the D; use zero, then you can search)

Fuel filter is easy & cheap but not very likely the suspect.

To DIY get an elm327 and check fuel trims.

 

Change the filter as JagV8 said but it's not likely the problem.

Most of the time those codes indicate a vacuum leak on that bank of the engine.
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