my car is an 04 signum 2.2 dti auto, while out in the car ive slowed down to come upto traffic lights and the engine has cut out on me without any warning ive put it in to neutral turned the key and its started just fine this has also happend to my wife which is abit disconcerting.I have since changed the fuel filter and air filter on the advice of the local mechanic but the problem is still there,any suggestion would be helpful.