right just recently my car has started being a bit funny when starting,put key in and turn and theres a weird noise like its trying to start but struggling couple of slow movements then fires up,and if i take a quick spin to shops or something and try to start again its like it doesnt want to again a couple of slow movements and its off,i've ordered new oil filter,oil,fuel filter and have read a lot on here about the crank sensor,is this a possibility ?? easy to change? expensive?