Check engine light
1996 T bird, 6 cyl, 100k miles. Had check engine light come on. Mech got an evap code, said most likely a loose or faulty gas cap. Gas cap is one year old so we did not replace cap with a new one, wife swears she always gets the cap to "click" a few times when closing it. Mech cleared the code. Next day check engine light came back on. I can have the gas cap checked, but I don't think that is the problem.
What should we be looking for next?
If the mech replaces the PCV or EGR is there a way to determine if the problem is fixed other than drive the car for a day to see if light comes back on??
Thanks for the suggestions