VEHICLE DESCRIPTION: ACCENT GT MODEL VEHICLES EQUIPPED WITH DOHC ENGINES MANUFACTURED FROM DECEMBER 19, 1996 THROUGH JUNE 30, 1997; 1998 ACCENT MODEL VEHICLES MANUFACTURED FROM MAY 6, 1997 THROUGH JUNE 25, 1998; 1997 SONATA VEHICLES MANUFACTURED FROM AUGUST 1, 1996 THROUGH JULY 9, 1997 AND 1998 SONATA VEHICLES PRODUCED FROM JULY 9, 1997 THROUGH APRIL 24, 1998. THE EVAPORATIVE EMISSION CONTROL SYSTEMS MAY APPLY EXCESSIVE VACUUM TO THE FUEL TANKS DURING THE CANISTER PURGE CYCLE. MINOR FUEL TANK DISTORTION COULD RESULT. A SMALL CRACK COULD DEVELOP ON THE UPPER FUEL TANK SURFACE. THE “CHECK ENGINE” LIGHT WOULD THEN ILLUMINATE AND, IN SOME CASES, THE VEHICLE DRIVER COULD NOTICE A GASOLINE ODOR.