Yeah, I get that. I'm not knocking your idea or anything, I appreciate you giving me your insight. I just don't think it's a possibility with the gas I just purchased. I've been using the same Chevron for 15 years and put it in everything I own. From the pressure washer, up to my Camaro that I track. Now, I do believe that there is still some bad gas in the tank, as I did not get every little bit of it out. There was probably half, to a gallon left in the tank. I would say closer to half a gallon though. Plus whatever was in the fuel pump sump and lines of course. Then, I added 6 gallons of 91 before starting it up. Then added that B12 now. I believe something else is going on. Since cylinder 5 is the only one that keeps coming up as a misfire. I think if it truly was bad gas, I would just be getting random misfires from everywhere or just the P0300 code. I was unable to get the scanner from my old shop this weekend. My buddy said that he will definitely get it to me for next weekend though. So for now, it will be on the back burner, but I will continue to fire it up and let it run to see if there is still a chance the bad gas hasn't been burned out yet. Thank you again for replying, I appreciate your insight as well as everyone else's!