my check engine light is on had it check machine said needed new gas cap repl on 2002 Dodge Durango

my check engine light is on had it checked computer said needed new gas cap; replaced it three times once with Oreily, one from 2002 Durango at savalge yard, and a new cap from Dodge; still on . Checked again with computer and computer still says need new cap could there be something else causing this?

by in Ozark, MO on November 21, 2012
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3 answers 2 comments
ANSWER by , March 11, 2016
Code p 0456 is small evap leak and they say it's the gas cap but, I replaced the gas cap and light came back on 5 days later. Where and how do you get the evap system tested?
ANSWER by , November 21, 2012
The EVAP system is spread from the gas tank to the engine. The code you had was probably for a 'large leak detected' and ONE of the possibilities is the gas cap , but that is as you've found not the only poss. cause. Less aggravation maybe , to have a qualified shop diagnose it. EVAP system leaks can be pesky.
COMMENT by , November 21, 2012
Thanks for help..... I appreciate it....
ANSWER by , November 21, 2012
i would check the evap system, vent solenoid and hoses you have a good chance leaking somewhere there
COMMENT by , November 21, 2012
Thanks for your answer however I still need some more help; where is this evap system and solenoid hoses? Are these the vacuum hoses? Thanks again.