Hi I have a Focus ST 2.5 59 plate, before Christmas it started showing engine failure and going into limp mode, it has been in the garage and had a full service and the fault diagnostics came up that the accelerator sensor was faulty, it has had a new switch today all seemed well but I've taken it out tonight and it the engine failure warning came up again although when I switched it off and on again it cleared, any advice would be welcome