How to Fix Code P0449 Evap Pics,Video and part #'s

Discussion in 'General Chevy & GM Tech Questions' started by Enkeiavalanche, Jan 2, 2013.

  1. undertheradar

    undertheradar Rockstar

    Just fixed my po449 code. Bought the "vapor canister vent valve" from Napa. Part# 600-1627. Cost was 94.99 they sold it to me for "garage cost" at $77.99. This valve is connected to the filter. I just uncoupled the one clip, turned the solenoid 40 deg and pulled it out. This is located at the front of the gas tank, drivers side frame. Very easy fix for a BS system. Everyone's solenoid is normally open and when u start the vehicle it closes for vacuum purposes. My solenoid was bad so it was venting all the time. I also bought a foot of 5/8" hose and connected it to the charcoal cannister on the tank. So nothing is moved. I blame the failure on a POS Mexico made solenoid. I ain't buying the relocation thing.
  2. j cat

    j cat Epic Member 5+ Years 1000 Posts

    change you fill up methods and you may be OK. if the canister is damaged from liquid fuel after a period of time this may return.
  3. undertheradar

    undertheradar Rockstar

    After a couple hundred miles, I now keep getting a PO446 code. I take the hose of the vent solenoid and can only blow air thru if the gas cap is off. Take the cap off and blow right thru it????
  4. ChevyFan

    ChevyFan The Sheriff Staff Member 5+ Years 1000 Posts

    Popular write-up! Nice work!
  5. Hal

    Hal New Member

    what about the code PO446. I have a 2005 suburban 2500,6.0 engine,what would be the fix for that
  6. j cat

    j cat Epic Member 5+ Years 1000 Posts

    what that means is the venting of the fuel tank is NO.... plugged up canister from over filling the tank then parking vehicle to allow the fuel to over flow into the charcoal.. then the damage .
  7. JimmyA

    JimmyA Member 2 Years 100 Posts

    Good Info, Thanks for posting!
  8. Enkeiavalanche

    Enkeiavalanche Loving the Outdoors Staff Member 5+ Years ROTM Winner 5000 Posts

    Glad to see that this has helped so many....:cool:
  9. Psyc0

    Psyc0 Rockstar 100 Posts

    Replacing the charcoal cannister and other EVAP parts only helped for a very short while.

    A friend who is a Cadillac Technician, advised Me to open the hood, open the large fuse and relay box, and locate a twenty amp (yellow) fuse C2, if memory serves.
    Pull that fuse, switch the ignition to on, then off, then replace that fuse.
    This action clears the memory of any codes in the PCM, according to My friend.
    Actually, I cancel the code first, with a scanner, then do the fuse magic.

    During springtimne, when the overnight temps fall to 40's to 50's in SW Florida, then rise to high 70's and low 80's, the EVAP system will set off a code.
    The rest of the year, no problem at all, because it's always hot down here.
    My friend had expanded the parameters on that pesky EVAP system, and We didn't have any problems for 7 years, until the Chevy Dealer replaced the speedometer, and re-flashed the PMC....then the code reappeared.
  10. j cat

    j cat Epic Member 5+ Years 1000 Posts

    if you fill up the tank then park it , you will have all these EVAP code problems.
    up north in winter when the fuel tank is filled then parked in a heated garage after a short drive this happens all the time.

    with a code reader/reset tool no need to remove fuses or disconnect the battery for a reset. many of the newer GM vehicles have had defective pressure transducers causing these codes also. many though do have damaged canisters with this design because the canister in next to and below the fuel tank . too close and too low.
    Psyc0 likes this.

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