How much 2 cycle gas? A gallon of "clean water free" two stroke gas is probably a darn good fuel treatment for any vehicle, unless you put several gallons in the tank! Marvel Mystery oil has been used for years and still is, it's about the same thing as this!! IF this gas was 'water free', that is NOT your problem! Question, why did you pour the weedeater gas in your car? Yeah i know you thought it was out of gas, that right? Fill the tank up with pump gas! Check engine light on? Scan test.
3oz of oil is not your problem! I am telling you this so you dont do all that work for nothing! You had a problem prior to putting this gas in the tank. Google Marvel Mystery oil. I ran a forest and garden shop for years so i know a bit about 2 cycle fuel and the oil mixed with it.
It 's trying to run on this gas only now so just FILL the tank with prem gas, that should take care of it. Then when you use some of that gas, you can put more gas in the tank and so on. It will not harm the engine! Get some gas in that empty can and put it in the tank.
First of all who keeps that much 2 cycle gas mixed up anyway? Now, you sure it wasn't DIESEL fuel??? Have it towed to a repair shop and fixed! That is all i can tell you! TWO CYCLE GAS RUNS PRETTY GREAT IN ANY AUTOMOBILE 4 CYCLE ENGINE THAT IS A FACT! I HAVE TRIED IT. DIESEL FUEL IS A DIFFERENT STORY!
Good luck with it.