My sisters 150 (79k miles approx) has recently been a bit crap on fuel, the computer shows 38-40 mpg. It got a bit better when it was mapped last weekend but she used to get 45+ out of it regularly.
I service it (oil, fuel filter, clean the K&N panel etc) as it comes due and was last done about 5k ago.
So, I'm going to clean the AFM next but was also thinking whether the DPF could be getting a bit clogged with the short journeys we do over here as it always runs better after shes been across to college with the motorway run.
Im impressed with its power now its been mapped though! Not as fast as my smelly nissan but very good for an aul derv and a possible replacement for my 4mo
Cheers
Nick