just brought a 99 EX-V6. after filling it up the check engine light came on.the gas cap is on securely. this is the first time i have experienced this, how long before it goes out?

 

Did you gas cap click at least 3 times when you tightened it? If it is your gas cap then it should go out in 3 days if im not mistaken.

 

It won't go out on its own. If it really was thrown by a not-completely tightened gas cap (I have done this several times on my 2000 LX) you still need to reset the ECU. Make sure you have the radio code (if you have the stock EX radio) and pull the "backup/radio" fuse under the hood. That resets the ECU. There are instructions in the DIY section.

 

In 1999 that fuse isn't under the hood.

Fusebox in the right-end of the dashboard, near the door hinges. Fuse #13.

 

Woops...I got it confused with my 95[&:].