error code

[mercuryrising]

i have a error code po456, something about emmison vac leak, says its not serious , but i cant stand seeing service engine lite on, does anyone have a idea where this is so i can fix it??? and exactly what is it?

thanks

 

[leftlane36]

I get the same one on our '03 and if I dont reset it in a few days the check gas cap light comes on. It happens to me boutevery 800-1100 miles not enought to really bother me. I got to a parts store or just unhook neg battery cable to reset it and Im good for another 1000 or so miles

 

[mercuryrising]

well i got a new gas cap, reset the system with a code reader. and so far it hasent came back on. i tryed reseeting it before it would just come back on with in a few min. so i think i nailed it....

 

[swetrid]

The usual problem is canister vent solenoid.

 

[mercuryrising]

i replaced gas cap reset code, it hasent came back on.. soit must have been bad.. glad its wasnt canister , i dont feel like even messing with gas tank..

 

[Exproblems]

i have a error code po456, something about emmison vac leak, says its not serious , but i cant stand seeing service engine lite on, does anyone have a idea where this is so i can fix it??? and exactly what is it?

thanks

>>>>>>>>>>>>>>>>>>>>>>

For that error code (PO 456) the Haynes Manual says the following: Evaporative emission (EVAP) control system leak detected, (very small leak)

On 2004 V-6 models, they have 2 EVAP canisters located on top of the gas tank and the 2004 V-8's and all earlier models have 1 EVAP canister. Not sure what engine you have. There are also several other components to this EVAP system, fuel tank pressure sensor, Fuel Vapor vent (FVV) valve, Canister Vent Solenoid, Fuel Filler Pipe Check Valve, Evaporative emission EVAP canister purge valve and the Evaporative emission (EVAP) dust seperator.
It says the most common symptom of a faulty EVAP system is the strong smell of fuel odor, mostly during hot weather. Says to make sure the gas cap is screwed on right or to inspect all the EVAP hose connections in the engine compartment and under the vehicle. Be sure to inspect each hose attached to the cansiters for damage or leaks. Replace if necessary. Also look for leaking fuel. Poor idling, stalling and poor drivability can be caused by a defective fuel vapor vent valve or canister purge valve, a damaged canister, cracked hoses. It also says to check for excessive fuel vapor pressure in the fuel tank. Just remove the gas cap and listen for a "whooshing sound" , if you hear this, the pressure inside the gas tank is excessive. Look for blockages or collapsed hoses. A complete test can only be done with an OBD-II scan tool. Take to dealership or qualified repair shop for professional diagnosis.