Just for the record:- same car, 53 plate,59000 miles, same symptoms,no fault codes,nightmare for 12days & then I decided to not drive it any more as my nerves were shattered.Booked in to main dealer & got myself green flagged up there.Dealers drove it & luckily it broke down 5 miles from base so they were able to get fault code P0340 come up---camshaft position sensor. Costs were £170-- Diagnosis £69,Labour 1 hr £69,Sensor & wiring/plugs £32. She flies like a bird again !!!