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Got a CEL the other day, and it has not gone away. Went to Autozone and got it scanned, and two error codes came back: both P0456. I searched the forums and have not found out what it really means. Anyone know? Should I be concerned?

My 6 is a 2004 6i ATX. No performance mods have been done (unless you count the K&N filter as one?)
 

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P0456 Evaporative emission system leak detected (very small leak) ON 2 Evaporative ´(DTC P0456)
 

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P0456 Evaporative emission system leak detected (very small leak) ON 2 Evaporative ´(DTC P0456)[/b]
Ok great.

Should I be worried? Or is it just that a hose ca me loose?
 

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if im not mistaken i think thats a loose gas cap but i could be wrong.. take ur gas cap off and put it back on and clear the code :)
 

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yeah, did it happen within like 10 min of getting gas?

since you do know what the issue is, reset it and see if it comes back. i used to get those from time to time....so i stopped turning off my car at the station.
 

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yeah, did it happen within like 10 min of getting gas?

since you do know what the issue is, reset it and see if it comes back. i used to get those from time to time....so i stopped turning off my car at the station.[/b]
Gas cap was fine, I checked that when I got it scanned. It wasn't within 10minutes of getting gas. In fact, the CEL came on a couple of days after putting gas in (my dad filled it up, so not sure when exactly), but I know I drove at least 30 (possibly more) miles before the CEL came on.
 

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Make sure the car wasn't running when he filled it up, or that he didn't top it off alot(shouldn't at all).

Both those things will do havoc to the Evap system.
 

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Make sure the car wasn't running when he filled it up, or that he didn't top it off alot(shouldn't at all).

Both those things will do havoc to the Evap system.[/b]
Oregon is not a self-service state.

Also, that 30miles number was wrong. Over a quarter of gas was gone at the time when the CEL came on, now that I think over it again. Probably drove close to 100miles since the fill-up when the CEL came on. Should I just reset the battery and see if it comes on again?
 

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Most common problem with this code is the gas cap was loose or it has failed to hold a vacum.

This code is a Two OBDII Trip code. Two drive cycles need to be complete before the computer will determine if there is a problem. This light will not set after ten minutes, unless, the computer was already going to kick out the code and you just happened to fill up the tank.

Note: Please people don't fill your tank with the car running, that is a hazard to yourself and everyone around you. Thanks

If you want go to Autozone and have them clear the code. Buy a new gas cap and see if the light comes back on. Our shop has a gas cap tester and would happily test it for anyone.

If the light comes back on you should get it checked out :)

P.s. The reason gas stations say do not top off the gas tank is because inside the gas tank there is a fuel tank pressure sensor. The computer uses this sensor in conjunction with other components to determine if there is a leak by putting a vacum on the gas tank and monitoring the pressure sensor for a significant drop. When the gas tank gets topped off it ruins this sensor.

65% of the time the gas cap was loose/bad
10% Fuel pressure sensor
10% EVAP Vent Solenoid
10% Purge Solenoid
5% Vapor Management Valve

Note: These statisitics are a rough estimation of what we see at our shop for every make and model we work on :)
 
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