give you all a bit of a laugh now, we had a vectra 1.8 16v ecotec in this week, ran fine till it warmed up then popping and spluttering and cutting out, took it up to drive vauxhall and they put it on tech 2, showed up crank sensor, got one ( £27 ), and then found out where it is, power steering pump off, air-con compressor off, auxillary drive belt and its tensioner off, engine mount off, bracket for pas pump and air-con commpressor off, dead easy from there just a little torx bit screw! all fitted back up and guess what, yep, still the same! the bloke i work with, Rob had a spare cam sensor so i changed that aswell no different, back to vauxhall, still saying crank sensor! got back to the workshop and i dont know why but i decided to go back to basics, guess what, no spark when warm! got a coil pack from the scrapyard, fine!!! left it running for ages and good as gold! not really sure what the moral to this story is, except we had to stand the cost of the crank sensor and fitting, but i'm not sure tech 2 is the miricle cure its meant to be!