I cant believe it, right when I decide to sell my car it starts acting up... I guess it doesnt want to leave me! lol
ok, I was on my way back home from college after a 3hr car ride. It was misfiring really bad but I said screw it and kept driving (stressed from packing the moving truck) the SES light turned on and it ran ALOT! better. But when I would slow down (about 10mph under what my constant speed was) it would turn the SES light off then it would run like crap again. welp, sorry to say but I had the same problem last spring it ended up that the water pump was leaking onto the opti/cap and rotor and seeped into it and caused misfire.
I am running really rich and the misfire/backfire happens almost always (not as bad when Im nailing it though) When stopped at a stop light its BAD too, sounds like ****!
Im just hoping that its not the same issue that I had before because Im trying to get rid of this thing. Tell me what you know and tomorrow I will try my hardest to get a scan tool on it.

thanks

 

Check the codes, will probably point to the opti.

 

figured... ill check them tomorrow