Well ive done a couple of tests. Ive disconnected the MAF and it ran better with more power. But as you know, Ive just fitted a new (well second hand) one which came off a running car with no problems. However, all this started after I drove through a field about month ago. (My band was playing at a biker rally in wrexham). It was thick with mud and it was murder trying to get out. I took to it garage and they cleaned it out and it ran a lil better for a while but recently its just gone from bad to worse. So im wondering as it under the car, maybe it was the sensor and Ive destroyed it driving through a muddy field. I will disconnect it the sensor and take it for a quick spin. Im still unsure what it could be because I said, when I disconnected the MAF it ran better (apart from the engine hunting like you would expect).