need some help with my engine.... well when i am driving my check engine light will go on and stay on for a while and then go off... at first it was blinking a code so i took it to mechanic and he fixed that... . then it starts up again and i brought it back. but he does a full check over every thing.. nothing . but it keeps going on and off.. i dont know why. has any one had a similar problem? or have a clue what might be wrong.... let me know thanks peace