that makes sense only prob dont have a reader can you suggest one i can buy cheap to do the job ? did plugs on nearside today to find a lot of oil in plug holes is this rocker cover gasket probs? engine not running right when i first start her up she wont idle until i give her a few revs can this be related to lamda sensor ? local garages not very helpfull dont think they know too much about rangerovers dont mind doing the work bu a bit feeling in the dark any help would be great