Recently got a 2005 Focus 1.6 diesel estate. Everything was running fine but after filling some Morrisons diesel in the car it became very sluggish. I put some more fuel in (Shell) and redex but still has immense problems getting up hills. Its ok if you hit the hills at speed but when you start from slow it basically grinds to a halt and 1st in high revs gets you up it yet when on the flat its fine.
Could it need a fuel filter change if got some dirty fuel in the system or the MAF sensor?? Any ideas greatfully appreciated.