I hear ya. I work six days a week and drive an hour to and from work. By the time I get home I'm ready to eat, shit, and get in the bed! I would definately get the cel checked to see what the exact code is. That will give you a more exact idea of what's going on. Who knows, it could be a bad o2 sensor or some other shit like that. I would definately get it checked before I spent a ton of time guessing and tinkering. Good luck and give an update if you get the code pulled.