Sorry, I am still not familiar with your Honda model but we are both getting the same codes..
...I had the same "Evaporative Emission System Leak Detected" code (though I thought mine read, "P1456". Maybe I was wrong on the numerical code but the description was the same. I had changed the gas cap a year ago but the CEL kept coming back but at a slower rate. I suspect I was losing fuel/mileage and that you are too. In my case I had an outright drip-drip-drip puddle forming fuel leak. Kinda scary since there should be no fuel in the EVAP system as I understand it.
I had the EVAP bypass valve and solenoid valve replaced ($180 parts+80 labor) and no CEL in over 800 miles and two fuel-ups so far, knock on wood. Jury's still out, but I will update my other thread in a few weeks when I am totally satisfied. Also, I can now hear the outright "swoosh" from the pressure retention when opening the gas cap to refuel, something I didn't hear before the work was done on the car. I hope that's a good sign that all is working well again.
I had developed a fuel leak that, thank goodness, forced me to identify and change the parts. I'm not saying you have the same problem, but just have a look at the thread below. I was away from home otherwise I may have tackled replacing the parts myself. Dunno. I'm weary so far of working on fuel-related problems myself. But it looked easy enough when I saw the removed parts--a couple of hoses attached, mounting bolts, and an electrical connector on the solenoid.
Look under your car for a leak with a cold engine and then again with a very hot engine--try at night with a flashlight, too--for fuel vapors (or obvious leaks). I was shocked to see both the leak and the steaming vapors (hot engine) coming off the EVAP system. I don't think even seeing the vapors is normal. It was probably the fuel leak and/or the fuel evaporating onto the hot parts.
Since the repair everything appears bone dry. No leaks, no vapors and no codes so far. Just a pleasing $260 "swoosh" sound.
Fuel Leak Help! ID Photos Please
P.S. The replaced parts are NOT shown in the above thread, just where it was leaking from/onto. I think they were contained in part in the smaller, fuel-soaked plastic box shown. Again, our cars are years apart so I'm not sure what your system looks like.