vauxal cavalier 2.0 auto?

My vauxal cavalier 2.0 L automatic keeps breaking down? The engine just cuts out without notice when driving along. If left for 10 to 15 minutes it will start up again drive for a while and then cut out again??? Someone has said it might be a sensor but which sensor is it?? The car has only done 76,000 miles on a K plate. Can you help.