I just got the check engine light on today with my 99 accord ex 4cyl. Checked the gas cap as mentioned in ower's manual. What would be the top 2 problems you think of or usually happen? And if I disconnect the negative connector from the battery for 2 minutes, will the light come back on even there is no problem or not come on while there is a problem?? Any advice or opion is greatly appriciated.

Thanks,
Haid