last couple of services i had my mpg dropped but its rectified itself after a week or so.
ill have to see how it goes then you think ?
Throttle body clean. And just have a snoop for split pipes. Also change fuel filter 
lol its a TDi no throtle body

and its had a new filter
but had bonnet open and i can hear a slite wissle so may have a small boast leak but not a clue where from.