that code is for a evap ( evaporative emmisons) system leak. this is kind of a tough code for you to diag at home. as d90212 said you need to smoke test the system with the canister purge valve closed. I doubt the regular bckyard guy has access to either of those scan tools or the smoke machine.
WDS if you use one has a nice easy to understand evap test that will let you know if there is a leak. but it will not test you where the leak is.
initially i thought it was the gas cap but not true in this case. i pulled this code a month ago. been pulling it every other week untill yesterday when i was taking it to the shop to get it fixed.
cause: the gas tank filler neck gasket was shot. which was a no brainer when you smell raw fuel. especially when you turn the car off. and you see drip right underneath the exhaust pipe passenger side. if you do see or smell this stuff, well that gasket is more than likely gone to the car gods.
mine had the raw gas odor and drip, the worst part was filling up and seeing my liquid gold leak out like a monsoon at the gas station which i honestly have to say was the most ass puckering moment upon realizing that it was dripping on the hot exhaust pipe.
should cost around 124 bucks to get fixed. mine just came out of the shop. apparently its bugun to be an issue since i had to have the part special ordered (it was the last one left at the parts supplier).