I had the same problem. It was the charcoal canister
Yes....this is it.
The way the EVAP system works is:
You put gas in the tank. As gas is filling up the tank, the air in the tank gets pushed thru the charcoal canister. The canister is a filter. This filter removes fuel vapors from the air. The vapors are collected in the canister. The filtered air then enters the "fuel tank vent tube", from here, this filtered air travels out of the vehicle, thru the pump hose, and down into the gas station storage tanks under ground.
There are times when the charcoal canister has collected so much gas vapors that the vapors turn back into liquid. When this happens, the liquid gas in the canister gets sent back into your gas tank to continue the cycle.
If the charcoal canister ever gets too much gas in it, the gas gets pushed into the EVAP system and into the engine causing a temporary "flooded" situation......and when it's really bad, it's very difficult to put gas in the tank because gas from the charcoal canister gets sent through the fuel tank vent tube into the gas station pump nozzle which causes the pump nozzle to click off repeatedly.
When this situation occurs and you replace the charcoal canister....... You'll also find that your gas mileage per tank has increased dramatically. So for instance if you were only getting 200 miles per tank, you'll now be back up to 300+ miles per tank.