pete i just have had my cam position sensor replaced,the car was stuttering on accelaration almost hesitant, but also this was an intermittent problem one day the car was fine next it felt like i was only running on 4 cylinders it took 3 visits to diagnostic to spot it, done my head in for about 2 month now its sweet.only about £35 + vat .so if it is that not to bad.