Thanks for the reply.

No, a reputable dealer put champion EON plugs in for me but only because the symptoms that I posted were becoming more severe. I seem to think that it might be electrical as the car is running sweet and then all of a sudden the revs drop off when idling to the point where I have to accelerate to get back above 1000rpm before it stalls. Even then tho the car starts to perform very erratic as if there isn't enough fuel getting through, hence the fuel filter change. I also noticed that the oil pressure gauge needle rises and falls when accelerating when stood, is this normal?

Cheers