Join Date: Jun 2006
Location: Eastern ON Canada
Car: 07 OBW 2.5i D-4AT
Feedback Score: 7 reviews
Was this soon after filling the fuel tank?
There have been reports of rusting of the filler tube leading to CELs due to incorrect pressure in the fuel tank. (Same as a loose gas cap.) But a hole in the filler tube would leak liquid only if the tank is overfilled up into the tube, which shouldn't be done because it can cause liquid fuel to get into the charcoal vapor recovery box (also up behind the right rear wheel). A flooded recovery system could give off fumes, leak gas, and cause a CEL.
If the filler tube is rusted where it enters the tank, it's possible that fuel would drip out, but I think the filler junction with the tank is more centrally located (although liquids can follow some strange routes before falling to the ground).
Other common sources of fuel tank related CELs include broken/rusted out vent lines (rubber and metal), and faulty vent valves.
Might want to raise the car, or otherwise have a look underneath to see if the source can be better identified.