Mine has had this for 2 years now, zero codes. Been too lazy to track down though. I only smell it when its warm or hot out, alot of threads i looked at was related to a valve connected to the evap canister. I have emissions due in june so ill see if i have to actually track it down. I would start around the evap canister when you smell it. Where are you smelling it, the front or rear of the car? Also does it happen when the gas tank is at halfa tank or below? Mines more towards the rear and can only smell it when im at half a tank or below.
Edit: ill try to find the thread i read on this but there was a way to check the valve connected to the canister, if i remember right you pull off one of the hoses and if you have gas in the hose the valve is bad. Maybe it was the bypass valve. Also tighten the gas cap about 5-8 clicks seems to help, one of the honda techs i work with said the 3 click oem cap should be tighten more or can still set a evap code for a amall leak.