bad gas

First, you can drain the tank from under neath. Put in new gas. Then disconnect the line after the filter, pump out the old gas. When you can smell new gas, that part is clean. Remove injector rail, drain and clean with carb cleaner. Do same with injectors, then test them with a 9V battery and see if they click. If all is well, put in a couple cans of good injector cleaner in the tank.

Yes it can be ran out. However, if it's effecting the running condition of your engine real bad and you have a long way to go before hitting the "E" mark, then I say drain it. If your not comfortable doing it, than any automotive shop should be able to do it. Otherwise your running the risk of crapping up filters, injectors, lines ect.