RE: check engine light question
usually a small leak is the gas cap being left loose - I would just get the code cleared and see if it comes on again. If it comes on again then you may have another problem (evap lines, cracked cannister, etc). Before you spend too much money on diagnosis which can get expensive fast at an average between 60-90 per hour you should know if there really is a problem. my advice as a tech is to get the code cleared, make sure your cap is tight every time you fill up, and wait and see if the light comes back on with the same code. save yourself some money.