I have a 2002 Accord and have had a ck engine light on since August P1457 Evap. Since then I have replaced the bypass solenoid, 2 way valve, purge valve, canister, and solenoid valve (over $700). Light is still on. Besides PCM (03-001 bulletin), is there anything else that can be causing this? I'm a student and can't keep replacing parts if it's the PCM that's causing all the problems. Any help is appreciated. Thx.:)

Gas cap gasket.

Check gas cap and hose connections. My first step would be to replace the gas cap--be sure to reset ECM afterwards. Even though the code for a gas cap leak is likely P1456, I would replace it to rule out a possibility it's leaking, especially after all you have done. I'm surprised you are encountering this problem on such a new Accord. I'm very interested in the solution, since it's such an unusual problem.

Just wanted to send an update for everyone. Finally was able to find the problem with this, it was an o ring that goes between the evap canister and valve. It was pinched, causing a leak. Light has stayed off so far. Now I am stuck with getting my money back from the Honda dealership, since they replaced a bunch of parts that there was nothing wrong with. Thanks for your input.