When my check engine light comes on my car starts bucking when i reach 3100rpm, But it doesn't do it all the time and mosttimes when i cut the engine off and cut it back on the light goes off and it drives fine. It was happenming once a week and know its doing it like 1 out of 3 times i get in my car the light comes on after about ten minutes and i cant go over like 65 miles per hour. I know that's not a good description but that's the best i could do. I have no Idea what it could be and my friend said it could be my map sensor going bad. any insight would be appreciated.