Toyota Repair: P0446 and Gas Filling Problem, vent hoses, fuel tank cap


Question
I have a 2005 Toyota Camry 4-cyl PZEV (California), auto-trans, 115K miles.  The engine trouble light came on and the OBDII code is P0446.  I've looked at the gas cap, but I do not think that is the problem.  The greater issue: when I tried to fill the tank at the gas station, the pump filler unit will not stay on (I tried on two pumps).  Last week, before the trouble light appeared, there was a momentary smell of gasoling in the cabin.  My guess is there is a perhaps a leak in the gas filler tube.  Your thoughts?  

Answer
Here are some problems listed that could be the cause of the p0446

Vacuum hose has cracks, holes, or is blocked, damaged or
disconnected
 Fuel tank cap incorrectly installed
 Fuel tank cap has cracks, or is damaged
 Open or short in vapor pressure sensor circuit
Vapor pressure sensor
 Open or short in EVAP VSV circuit
EVAP VSV
 Open or short in CCV circuit
CCV
 Trap canister assy
 Fuel tank has cracks, holes, or is damaged
 Charcoal canister has cracks, holes, or is damaged
 Fuel tank over fill check valve cracks, or is damaged
ECM
Notice that the most likely cause is the first one and the least likely the last(ECM)

I would recommend checking the hoses at the charcoal canister and the vent hoses on the fuel tank as well.