If your vehicle is showing visible fuel puddle or dripping under the vehicle, here are the most likely causes and the parts you'll need to fix each one.
The fuel filter is a common maintenance item. If the fittings are not tightened properly or the crush washers/seals are pinched during a recent replacement, pressurized fuel will leak rapidly while the engine is running.
Over time, metal fuel tanks can rust from exposure to road salt and moisture, or plastic tanks can be punctured by road debris. This results in a constant drip or puddle under the rear of the vehicle.
Often occurring after a recent fuel pump replacement, if the lock ring is not fully seated or the rubber gasket is pinched, fuel will slosh out of the top of the tank, especially when full.
The metal tube or rubber hose connecting the gas cap to the fuel tank can rust or dry rot. This typically causes a puddle specifically during or immediately after filling up at the gas station.
The rubber O-rings that seal the fuel injectors to the pressurized fuel rail can dry out and crack, or get torn during engine work. This causes fuel to spray over the engine and eventually drip to the ground.