Getting the 99 Civic ready for echeck

Working on getting the car to pass e check still, second mil that needs to go is p1457, leak detected in evap canister area...any honda guys or any techs out there know the culprit, how to fix/diagnose the problem, or what to do...Alot of people point to the vent shut valve, ect. and this is all uncharted waters to me...any help is appreciated, thanks

Just finished ordering a O2 sensor simulator, way too many people say it works and it seems pretty impressive as to how it works, so once I get it I'll let all of you know how that works out, so anyone who has the cat. defficiency mil code thrown, you may be able to get rid of it, updates to follow later