SES light

My SES light came on a few weeks ago and I ran it to Autozone, They gave me the code P0442, Emissions leak (small). I then had the guy clear the code and it stayed off for about a week. It came back on and I ran it up there again and it has the same code. What should I do to fix the problem?

A flaky or loose gas cap to include seal can cause P0442 Small Leak Detected. Check condition and tightness of all evaporative emissions lines at the rear - gas tank, charcoal cannister, vent solenoid and then all lines at purge solenoid on the engine side.