reloaded.sidd

Hi....I have a 2000 Honda Accord SE which has around 109k miles on it...Recently, the system check engine light went on a friday...i drove it all day and night on thursday ... nothing happend...then on friday in the afternoon on a casual drive it turned on...even after the light turned on...nothing really happend..the car was the same as it was before the light turned on...i would have never noticed until i wanted to check the mileage on my car...i thought it was something to do with my gas as i was on reserve...here i observed something...when i tried to open the gas cap...i felt it was a bit loose...i thought it had nothing to do with the systems check engine light..so i filled abt 2 gallons and this time i made sure that the gas cap was closed tightly and securely...still the light persisted...i took it to a mechanic who told me that they were closed for the day and asked me to get back to them on monday....meanwhile i got the systems test done at walmart which showed everything was good..i made a few small trips (10-15 miles in total) meanwhile within the town...on monday.i took my car to KWIK CAR who advised me to get a diagnostics done for free at OREILLY as it would cost me 40 bucks if i got it done with them...i went to OREILLY who checked the car and diagnosed the code as P1456...i took it back to KWIK KAR...after i got back to them, the mechanic wanted to see what was wrong and at that point the light was not turned on...this confused me and i went to OREILLY again and got the test done and at that point it showed no error code...i dont know what to make of this...i need to make a long trip and i am not sure if this would be advised?? Please tell me what to do...is there any serious problem that i need to get fixed immediately and how much would it cost...or is there something that i could do it myself and avoid all the hassles????

Looking forward for your reply
Sid.

davey5300

p1456= EVAP Emission Control System Leak Detected (Fuel Tank System)