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Old 09-03-2012, 11:33 PM   #1
Scooby Specialist
Member#: 273906
Join Date: Feb 2011
Chapter/Region: NESIC
Location: Nonsense Poopy Pants!
2003 Outback

Default P0440 EVAP code - Test conditions?

Hello, I know that this EVAP code has been talked to death on this and every other Subaru forum, but I have a specific question.

I've heard that keeping the gas tank nearly full (above 3/4 tank or so) will prompt the system to not run the EVAP test. Can anyone confirm this, refute this, or extrapolate upon this? Or point me in a direction...I'd like to know more about how the EVAP system conducts tests.

The reason I am asking is because this car has to go in for its emissions retest in less than two months. If it does not pass it will be illegal to drive. I do not intend to ignore this problem, but I've already got two codes (P1507 idle code and P0420 cat code) to fix. I anticipate these codes to be relatively easy to fix, but they will still require time and money, neither of which I have much. So I'd like to bypass the EVAP code for now, if possible.

Any input is appreciated.

EDIT: Car in question is a '99 Impreza Outback Sport 5mt

EDIT2: The "source" of where I heard this gas tank rumor is from a couple Subaru forum members...but I can't remember which forum specifically and I'm not able to find the thread(s) again.
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Last edited by tibug; 09-04-2012 at 12:09 AM.
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Old 09-04-2012, 01:21 AM   #2
Scooby Specialist
Member#: 273906
Join Date: Feb 2011
Chapter/Region: NESIC
Location: Nonsense Poopy Pants!
2003 Outback


Woohooo, found it. The information was in an old Endwrench article (God, they're awesome) that can be found here. Here's the part that I was interested in:

The testing of this system is only
conducted once per drive cycle and
only under very specific conditions:
• The fuel tank must contain less than 9.6
gallons of fuel.
• The fuel temperature must be less than
• Engine speed must be over 1500 RPM.
• Vehicle speed over 28 MPH.
• Throttle position must be mid-range.
• Intake manifold vacuum must be
equivalent to cruising vacuum.
• 455 seconds must have elapsed since
engine start.

I guess I'm gonna fill my tank up every time I see a gas station and see where that takes me.

FYI A lot of Endwrench articles from the now defunct Endwrench site are available here.
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Old 06-10-2013, 01:50 PM   #3
Scooby Newbie
Member#: 359062
Join Date: Jun 2013

i have the same problem, i have a 2004 impreza that i just bought two days ago. its throwing a evap code, the inside of my car smells like gasoline,im getting horrible gas mileage and my idling is off it either idles at 700 to 800 rpms or goes up to 2000 rpms, the guy i bought it from replaced the fuel pump and gas cap. any ideas?
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