Edmunds Answers



  • karjunkie 08/23/08 8:01 am PST

    PO456 is an OBDII code that indicates a small leak in the EVAP system within the emissions system. The emissions system pressurizes the evap system at cold start-ups to check for any fuel vapors escaping into the atmosphere. If there is a leak, the PCM burns a code and hence, a check engine light appears. First check to make sure your fuel cap is on tight. This is the usual reason for the MIL to come on and trigger this code. If this does not work, check the hoses between the vapor canisters. A cracked hose between the forward vapor canister and the rear vapor canister is also a common reason for the code. You can easily repair this yourself with a new hose for a few dollars at any auto parts store.


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