Check engine light

My check engine light has come on about a week ago, I went service and they tighten the gas cap and check engine light is gone, but I just got the check engine lights on again,
I tight the gas cap but it's still there. I plan to go long trip yesterday, so do you guys think it is going to be a big problem or just nevermind for now?

thank you.

leeverite

nevermind for now, but you probably have a purge leak

service find out , it's an air dedector fault, they replace it and the lights gone. it's small part but pretty expensive if you don't have a waranty.
thanks!

Codes must be retrieved from ME computer before any assumptions are implemented.
A small leak in the EVAP system ie: loose gas cap, not a big deal, however if the self-adaptation is out of whack, drivability can be affected.