PLEASE HELP P1457 emission code

Whats up A.F, a few days ago i installed a "RearSection Exhaust" on my 98 civic ex.... drove for 2-3 days on the 3rd day the "check engine light" comes on...i look up the code and i get P1457 (Evaporative Emission Control System Leak Detected(Control Canister System) Does that mean i have a leak on the Rear Section of the exhaust where it connects??? Tighten the Nuts so leak goes away??? im not too sure about this Code...Can Some please help me????
thanks

evaporative emissions controls are to prevent gasoline from evaporating and escaping into the environment. The system includes your gas cap, as well as other components to prevent gasoline vapors from escaping. Many vehicles use a charcoal-filled canister to absorb gasoline vapors.

The first thing to check would be your gas cap...

always tighten at least 3 clicks or it says right on the cap that the check engine light can come on.

thats prolly your problem, tighten the cap on the tank 3 clicks, then drive around for i think honda says 3 more days, then the light should go off.