CEL: p0457

Zach

New member
2003 WRX Stage 2

I pulled the codes on my car today the code reader said I had two P0457(Evaporative Emission Control System Leak Detected) codes so while I was at work I bought a new gas cap and reset the ECU on my way home the light came back on and the codes where the same. What elese could it be?

I also checked the small blue hose under the intake manifold to the left of the alternator and that hose was conected aswell.

 
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I did some pokin around and really the only noticible thing I was able to find was the metal plate under where you screw the gass cap onto (where the threaded part sticks out) is a little rusted but i didn't find any holes other then the one that is ment to drain the water.

 
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got same code over weeknd on 00 RS2.5. Cleaned crud off filler neck and sealing ring on cap...presto no mo code throwed. I think this "Evap system Leak" code also happens more in super-hot weather, cuz heat maxes out fuel vapor pressure in tank, lines and evap system.

 
Replaced the gas cap with a new one from Ever Green and the code went away for about 120 miles but now its back.

 
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^^ this.^^

Pull off Right Rear wheel.

Pull off the black plastic fuel filler pipe cover and have a look.

Poke with screw driver.

Order parts.
I'd order the filler neck BEFORE poking at it though lol those things are such a pain

 
I have the same code on my 04 obs. Tried a couple gas caps I had laying around.  Pulled cover, found ickyness.  I aint fixin jack until I pump 5 gallons and 2 gallons go on the ground. 
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 Mine is wicked rusty up by the vent valve.

j/k ...my wife will make me fix it this spring

 
I assume Subaru has an evap purge valve .You could also pull vacuum on the valve with a hand pump like a mightyvac and see if it holds vacuum. If it doesn't there is a torn diaphragm in the valve .

 
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