Quick fix for code p0446 evap emissions vent circuit low.

Discussion in 'How-to Guides' started by kinglt1, Feb 17, 2009.

  1. Muzzer1965

    Muzzer1965 New Member

    P0446 Hummer H3 2006

    Hi, I live in England and own a 2006 Hummer H3. I have the P0446 code, and changed the Vent solenoid for a new one (It is the same ACdelco part number) I just needed to remove a small electrical extension as the female electrical socket was not the same. I cleared the code and a day later the code P0446 was back. The car has only done 30000KM. I think I will have to blow out the pipework, check the electrical supply and make sure the new unit works. The problem is that there is only one Hummer dealer in the UK, and they are miles away, and that is why I have to do it myself. I have spent days searching the internet, and this site is much more informative than any others I have found. Has anyone got any other suggestions that I need to try whilst I am working on the vehicle. This is my first post, so hoping for some good information.

    regards from across the pond!
  2. MyDenaliSux

    MyDenaliSux New Member

    I have a 2003 Denali and it's been throwing alot of codes lately. Today's code is the P0446. Would this cause the engine to run rough? The previous code was for running too lean bank 1. I cleaned the air cleaner and MAFS and the code went away on its own. A few days later..this one shows up. But this seems like a easy fix. Thanks for the info.
  3. TBark

    TBark New Member

    Great info kinglt1 and wayned.
    One question on the new 2 pc kit.
    The hose from the left side of the old filter, not used with the new 2 pc kit,
    where does that hose come from, or go to ?

  4. TBark

    TBark New Member

    Sorry, it's on the right side and hose must go to the gas tank top ?
    So to understand, Clogged lines or filter, or valve stuck close would be code PO446,
    and if stuck open would be code PO449 ?
    I guess either way the new 2 pc kit would be needed.

  5. Enkeiavalanche

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

    Very good info.. Still gotta fix mine,,, It's getting cold here and my remote start will not work till this is fixed..:grrrrrr:
  6. TBark

    TBark New Member

    My engine light is on and my command start still works.

  7. wayned

    wayned Rockstar 100 Posts

    Is command start the same as remote start.
    Mine would not work with the en. light on.
    07 nnbs pu 5.3
  8. Enkeiavalanche

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

    Factory remote starts will not work with a Emission problem.

    - - - Updated - - -

    Ok switched to my Winter rubber and stock rims tonight So I got under the truck and took some pics and look at a few things.. evap1.jpg
    evap1.jpg evap3.jpg This is above the rear and next to the tank evap2.jpg
    This is in front of the extra tire I took it apart tonight and still have 0449 code...
  9. TBark

    TBark New Member

    My command start is not factory, Compustar or something like that.
    Works just fine with engine light on.
    Anyways, just got confirmed shipping on the new emissions valve kit off EBay, $84 all in.
    Will use wayned's video to help install.
    Thanks for the help people, great info on this site.

  10. Joejoe

    Joejoe New Member

    Hey guys, newbie here lol...i have the dreaded p0446 code and i wanna try blowing it out before spending money...i think i found the vent valve but it looks different than all the pictures i seen, i have a 2001 sierra reg cab long box...

    Here is a pic

    Attached Files:

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