WHILE DRIVING AT ANY SPEED ON THE HIGHWAY VEHICLE STALLS INTERMITTENTLY, AND BY DOING SO, IT CAUSES STEERING WHEEL TO LOCK. VEHICLE HAD BEEN IN DEALER'S SHOP FOR FUEL PUMP REPLACEMENT. AT THE TIME OF FUEL PUMP REPLACEMENT MECHANIC BROKE THE PLASTIC COUPLING THAT CONNECTED THE FUEL LINE TO THE FUEL TANK. THE BREAKING OF THE COUPLING CAUSED AN EXPLOSION TO OCCUR IN THE FUEL TANK. *AK