What NHTSA says the defect is
VEHICLE DESCRIPTION: PASSENGER VEHICLES. THE NON-RETURN VALVE INSTALLED AT THE LOWER END OF THE FUEL FILLER PIPE CAN STICK DUE TO INSUFFICIENT CLEARANCE BETWEEN THE VALVE CASE AND THE VALVE SHUTTER COMBINED WITH THE MATERIAL PROPERTIES OF THE FUEL HOSE BETWEEN THE FILLER PIPE AND THE FUEL TANK.
The risk NHTSA states
THIS CAN CAUSE A "HARD TO REFUEL" CONDITION, AND IN SOME INSTANCES, A "FUEL SPIT BACK" DURING REFUELING.
The remedy NHTSA states
DEALERS WILL REPLACE THE NON-RETURN VALVE WITH A MODIFIED RETURN VALVE.
Campaign 00V032000 · reported to NHTSA 7 February 2000 · Read it on nhtsa.gov →