quote:

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Originally posted by mtbaughs:
disconnect the battery and re-scan

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what he said
 

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Posted by BlueOvalRacing (Member # 1531) on :
 
you left your gas cap off, that was the leak
 

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Posted by wilit (Member # 3367) on :
 
Your gas cap probably needs to be replaced as it doesn't hold pressure any more.
 

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Posted by 1BAD2V (Member # 2495) on :
 
it's the second time it happens, happened to me 2 months ago, I unplugged the battery then I didn't get a light (gas cap light, further right ) for 600 miles. The light came back last week and this time with a Check engine light (after 2 times u get that light, then u also get a check engine light from what i found on the obd2 book...). Might be the gas cap that doesn't work anymore...
Thanks for ur help.
 

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Posted by TRIX02GT (Member # 2844) on :
 
I had the same exact problem and i brought it back to the dealer and they said that it was an evap. valve on the charcoal canister i believe they replaced it under warranty. (po457)

Not sure what they other code is....hope that helps ya.
 

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Posted by 88bird (Member # 1424) on :
 
Could be a number of things, If you know you haven't left the gas cap loose, then in my experience the vapor management valve is bad. Its located in the right inner fender. Pretty common failure for 99-up mustangs. But needs proper diagnosis to be sure. As far as the codes gom, the vehicle needs to be driven for about a week (2 drive cycles, where the pcm is able to test the evap system) before you know that it has been repaired. You can disconnect the batt and the codes will go away, but if the problem still exists the codes will return.
 

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Posted by TRIX02GT (Member # 2844) on :
 

quote:

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Originally posted by 88bird:
Could be a number of things, If you know you haven't left the gas cap loose, then in my experience the vapor management valve is bad. Its located in the right inner fender. Pretty common failure for 99-up mustangs. But needs proper diagnosis to be sure. As far as the codes gom, the vehicle needs to be driven for about a week (2 drive cycles, where the pcm is able to test the evap system) before you know that it has been repaired. You can disconnect the batt and the codes will go away, but if the problem still exists the codes will return.

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Exactly what i did....pulled the neg and the light went away for a little while. Did it again and it stayed off for about 1-2 days and then the light came on again so i brought it to the dealer.

I'm sure you'll get it worked out soon.


 

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Posted by 1BAD2V (Member # 2495) on :
 
yep..thats what happend...unplug the battery the nthe light went away and came back...I'm gonna get a new gas cap and test if that work..if not I'll ask a shop to look at the valve thing..thanks guys !!!
 

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Posted by 88bird (Member # 1424) on :
 
My money is on The vapor management valve, located in the rh inner fender. Typically a bad gas cap will give you a p0442 (evap small leak).

If you wanna get it yourself and install, its pretty easy. The basic # on the part is a 9c915, so take this number when you go to the dealer to buy one.

Just some help, hope it does.
 

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