I have a 53 plate expert 2.0 hdi 85000 miles, it had a service about 6 months ago, fuel,air and oil filters changed, on Sunday I was driving on the motorway and noticed that the power was dropping off, at a steady throttle, then it would pick up again. At the next roundabout it cut out, but started again first time. Now when driving it feels like it is holding back, then it pulls away like there is nothing wrong, it still cuts out when slowing down, buts starts ok. Does anyone have any idea whats wrong. I have checked the air filter, its clean. I have taken it to a different petrol station and filled it up (thinking the diesel may have been contaminated). Any help would be greatly appreciated.