The Nissan Path

Dear all,
in the last months I had a service engine soon light going on and off. Advance auto parts reported being a small gas leak. I got a new gas cap, but the light is there after several engine cycles.
How to fix this issue?
Thank you

Year/make/model of vehicle and the stored code number will be required to help you. If they had you replace the gas cap, I'm assuming it's not a small gas leak, but a problem with the evaporative emissions system, which is used to store gas vapors from the fuel tank until they can be later sent to the intake manifold and burned through the combustion process of the engine, rather than have the fuel vapors exit into the atmosphere.