Since last Friday, my car has been stumbling for about a second, then resumes OK. When it stumbles, the check engine light usually comes on, but does not stay on. Other than this, the engine seems to run just fine. I experience this especially when I start from a stop sign and when I push the gas pedal a little hard, but it happens in higher speed as well occasionally. When I accelerate slowly, I don't have this problem. I just changed the fuel filter, spark plugs, and added a red line fuel system cleaner in addition to a new air filter. It has been only 2 weeks since the oil change. I visually checked the wires and hoses, which seem okay. What is going on? Did anyone have similar problems and how did you guys fix it? What everyone thinks? Any help is appreciated! Thanks