02 chevy tahoe

MY TAHOES SERVICE ENGINE SOON LIGHT CAME ON.SO I TOOK IT TO AUTO ZONE,AND THEY GAVE ME A CODE (PO452) EVAPORATIVE EMISSION CONTROL SYSTEM,PRESSURE SENSOR SYSTEM COULD SOME ONE HELP ME FIX THIS.

first step is a new gas cap and rotare it enough to get several clicks every time you put it back on. If that is it, light should reset in 4 or5 days of driving.