Yesterday i came here and asked about maybe putting a solution in my radiator cause its blew and is flowing like a river. my toyta isnt working so i had to drive it to the store now the check engine light is on and its flashing. the truck sounds HORRIBLE!!!! It sounds like its drowning. and now its reading a code P0303. I know its cylinder 3 misfiring, but why is misfiring all of the sudden? Is this a major problem? Is it something that a home mechanic could possibly do or will it have to go to some expensive mechanic shop? PLEASE HELP PLEASE!!