My brother had something simular happen only it was that the gas he bought had water in it and car ran like a lawnmower. He had an electric fuel pump so we disconnected from carb and just let it pump it all out into a gas can. i remember seeing somewhere that on the connector to pull codes that there is a terminal you can jump and it runs the fuelpump continuously. Then all you'd have to do is disconnect the line from the fuel rails and run a piece of hose to a fuel can and take out a few gallons .
here where i found the info on running the fuel pump.
http://www.mustangworks.com/articles...-iv_codes.html