Car is misfiring a lot lately

Hello my name is Dave.

I suspect you are on the right track thinking it could be related to it having bad gas even though it sounds like you have used most of the old gas the damage it could have possibly caused would remain. With your issue of the engine stumbling when taking a turn leads me to believe that the hose/rubber isolator for the fuel pump in the gas tank have deteriorated allowing the pump to move out of the fuel while taking a turn and the level is low. The other parts commonly damaged by old fuel are the fuel filter and fuel injectors. I would recommend starting with the fuel filter and having the injectors professionally cleaned however I would also recommend at least inspecting the fuel pump which is in the gas tank which would have to be removed to inspect/replaced. I have attached a diagram of the fuel system so you can see where the filter and pump are on your car. I hope this helps you find a solution and thank you for using 2CarPros!