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  1. #1

    Default My Cavalier is throwing P0440

    I know it's not a truck, but my 1999 Cavalier is throwing a P0440 code - EVAP small leak, no flow condition.

    Four probably causes.

    1) Defective fuel cap
    2) EVAP canister or host cracked
    3) Purge of vent solenoid defective
    4) Vacuum leak at engine.

    Anyone have experience with this code? I guess I'll just start at the top and work down.

    10 Chevy Traverse LT AWD
    02 Chevy Trailblazer LS (110K+ miles - loaded except for 4WD - WRECKED!)
    99 Chevy Cavalier LS (105K+ miles - commuter car)
    78 Chevy Suburban Silverado (454, 3/4 ton)
    62 GMC 3/4 ton Pickup (350 police interceptor)

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  2. #2


    Start with 4,
    Then 2, they are kind of related,
    Then 1,
    And lastly 3
    Start with the ones that cost no money to check.

    Technology is great, when it Works,
    And one Big Pain in the Ass When it Doesn’t.
    Detroit Iron Rules, All the Rest are Just Toys.
    94 GMC Burban, 5.7L (350), 4X4, Auto
    86 GMC Burban, 350, 2 WD, Auto
    79 GMC pickup plow truck, 400, Full time 4X4, Auto
    86 Pontiac Fiero SE, 2.8L, Auto, only mid engine American car
    See a Pattern yet?

    15 year GM assembly line worker.

  3. #3


    That's basically my plan.

  4. #4


    I think I posted this in another thread. I cleaned up the gas cap and the filler cap insert and got rid of some grime, I let the system run a couple of cycles and the code reset itself and hasn't come back.

  5. #5
    Jr. Engineer Gmcsuvguy's Avatar
    Join Date
    Dec 2007
    Alberta, Canada


    I've seen them leak at the fuel sender unit o-ring on the tank. Try the little (easy) fixes first, or take it into a shop that has a smoke machine, they hook up the smoke machine and pump smoke through the evap system and look where the smoke is coming out from.
    Ken Beida
    2010 GMC Sierra Crew Cab 4X4, 5.3L
    2009 GMC Sierra Denali, 6.2L = 403hp, AWD, Full load

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