1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

P0446 Error Code Question

Discussion in '1st Gen. Tacomas (1995-2004)' started by Colonel Troutman, May 1, 2009.

  1. May 1, 2009 at 12:57 PM
    #1
    Colonel Troutman

    Colonel Troutman [OP] New Member

    Joined:
    Mar 8, 2009
    Member:
    #14466
    Messages:
    4
    Gender:
    Male
    Littleton, CO
    Vehicle:
    99 SR5 TRD
    I have a 99 Tacoma with 3.4L V6. A while back the check engine light came on, so I invested in an OBDII tool to see what was up. It reported an error code of P0446. I ran this by a buddy who is a mechanic and he said to try replacing the gas cap. I did this and cleared the code and everything was fine for a few weeks, then it came back again yesterday with the same code. Has anyone run into this before or have any advice on what might be causing it? Thanks.
     
  2. May 1, 2009 at 2:10 PM
    #2
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Staff Member

    Joined:
    May 8, 2008
    Member:
    #6497
    Messages:
    104,126
    Gender:
    Male
    First Name:
    FlimFlubberJAM
    Tenoe, AZ
    Vehicle:
    2013 Rubicon Unlimited,
    4.10 gears, sliders, and lots of buttons.
  3. May 1, 2009 at 4:21 PM
    #3
    Colonel Troutman

    Colonel Troutman [OP] New Member

    Joined:
    Mar 8, 2009
    Member:
    #14466
    Messages:
    4
    Gender:
    Male
    Littleton, CO
    Vehicle:
    99 SR5 TRD
    Thanks for the quick reply. Looks like it may be a little over my head. This what happens when you have a "buddy" who's a mechanic I guess...
     
  4. May 1, 2009 at 5:07 PM
    #4
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Staff Member

    Joined:
    May 8, 2008
    Member:
    #6497
    Messages:
    104,126
    Gender:
    Male
    First Name:
    FlimFlubberJAM
    Tenoe, AZ
    Vehicle:
    2013 Rubicon Unlimited,
    4.10 gears, sliders, and lots of buttons.
    It shouldnt be to hard to fix. Identify the location of the part on the truck, and take your time. Its all just nuts and bolts. :)
     
  5. May 1, 2009 at 5:13 PM
    #5
    Blackened Taco

    Blackened Taco Well-Known Member

    Joined:
    Nov 14, 2008
    Member:
    #10771
    Messages:
    594
    Gender:
    Male
    First Name:
    Tony
    Virginia
    Vehicle:
    2005 AC 4WD TRD Sport Tacoma Speedway Blue
    3 inch suspension lift, 16 inch TRD FJ Cruiser black alloys, 33 X 12.5/16 Swamper Trxus M/T, Line-Xed Toyota skid plate, TRD exhaust, TRD cold air intake, Full tint to match factory tint, In channel wind deflectors, Custom wired hidden XM, Black shorty antenna, Black background headlights, Sockmonkey TRD decals, Kenwood 5120 HU with navigation, Boston Acoustic SL60 front compnonent speakers, SL65 rear speakers, Grillcraft lower mesh grille, Black badging, AromorTech Offroad rear bumper and rear shackle flip kit Access tonnosprt cover, 12 volt power adapter wired in under the dash for standard plug in items. Recently added Devil Horn Toyota Logo, Thanks Andres.
    p0446 code is an evaporation leak code, also p0440, p0441 and p0456, could be as simple as a loose gas cap, most common would be a charcoal canister. but you have a leak in the fuel tank region. If the gas cap was replaced and you used an aftermarket gas cap it may also be leaking as well due to a poor seal. Most likely though it is a charcoal canister.
     
  6. May 1, 2009 at 6:55 PM
    #6
    Colonel Troutman

    Colonel Troutman [OP] New Member

    Joined:
    Mar 8, 2009
    Member:
    #14466
    Messages:
    4
    Gender:
    Male
    Littleton, CO
    Vehicle:
    99 SR5 TRD
    Thanks again. I used an OEM gas cap and it's on nice and tight. I'll look into the charcoal canister. Sooner or later I just have to tear into it and scrape a knuckle or two. Where exactly is the charcoal canister located? I think the next thing I invest in will be a Chilton's manual.
     
  7. May 1, 2009 at 7:03 PM
    #7
    BeefTaco

    BeefTaco WESTern Alliance: NORCAL COAST

    Joined:
    May 8, 2008
    Member:
    #6481
    Messages:
    631
    Gender:
    Male
    Santa Cruz County Ca.
  8. May 1, 2009 at 7:16 PM
    #8
    Colonel Troutman

    Colonel Troutman [OP] New Member

    Joined:
    Mar 8, 2009
    Member:
    #14466
    Messages:
    4
    Gender:
    Male
    Littleton, CO
    Vehicle:
    99 SR5 TRD
    Awesome, thanks BeefTaco. Now I have something to do tomorrow!
     
  9. Sep 29, 2014 at 12:59 PM
    #9
    Tacotime99

    Tacotime99 The Angry Taco

    Joined:
    Jul 24, 2014
    Member:
    #134585
    Messages:
    98
    Gender:
    Male
    Vehicle:
    99 Tacoma SR5
    Bumpers Sliders Skid plates 33" tires
    Thread revival! (real question below)

    This is the number one thread when I searched "Tacoma P0446" on google...wow...

    Ok so on to the problem, since this thread is out there already no need to make another.

    I have a '99 3.4L (5VZ FE) that throws the P0446 code on occasion. I'll clear it and won't come back on for a couple days to a week or longer (depending on the driving i'm doing). I see a faster return of the code with in-city stop and go driving, where as longer road trips won't kick the code on at all. There are no other codes that come on with this one at all. This has been ongoing for about 3 months now.

    That being said, I replaced the gas cap and tested the VCV (it was within spec). What are my next steps that I should take to put this thing to bed?
     
  10. Sep 29, 2014 at 1:07 PM
    #10
    Crock112

    Crock112 Well-Known Member

    Joined:
    Oct 20, 2013
    Member:
    #114844
    Messages:
    63
    Gender:
    Male
    First Name:
    Crock
    New England
    Vehicle:
    Stock SR5 (for now)
    Bull bar, nerf bars
    Just piggy backing off of Tacotime- I'm having the same code and once in a blue moon it throws P0441. I realize it's most likely the charcoal canister, but am mostly wondering what the risk of ignoring it is. Truck runs just fine, the only quirk is I sometimes have a hard time filling the gas tank. The air doesn't escape fast enough as the fuel goes in, so the fuel backs up to the top quickly and kicks the pump off.
     
  11. Sep 30, 2014 at 7:55 AM
    #11
    Tacotime99

    Tacotime99 The Angry Taco

    Joined:
    Jul 24, 2014
    Member:
    #134585
    Messages:
    98
    Gender:
    Male
    Vehicle:
    99 Tacoma SR5
    Bumpers Sliders Skid plates 33" tires
    So mine came on again today after sitting at a stop light. It's been about 8 days since it last came on and most of my driving was highway over the weekend and before.

    Can anyone lend some assistance or suggest solutions (taking into account my trouble shooting done already)?
     
  12. Dec 15, 2014 at 8:41 AM
    #12
    aztacoma1

    aztacoma1 New Member

    Joined:
    Dec 15, 2014
    Member:
    #144306
    Messages:
    1
    Gender:
    Male
    Arizona
    Vehicle:
    02 Tacoma
    My truck was throwing the Evap codes and I spent some time hunting down the issue, eventually had to use a home made smoke system on it but figured out that the fuel tank vent valve was the cause of the issue (as a result of this is where smoke was coming out of and should not have been)

    This is a plastic valve assy that goes from the top of the tank over to the charcoal canister (how the vapors get to the canister). When I was getting parts the dealer told me that the seal will age and crack or the valve, again made of plastic, can break. I have highlighted in the attached with red arrow the part I had to replace.

    After dropping the tank I found that there was a hairline crack in the plastic valve housing, which was creating the leak. While I had the tank out I replaced the seal and hoses associated with this valve. Total in parts will run ~100-150 depending on if you go dealer or online purchases, this included the hoses and seals which probably were fine, however if I am dropping the tank spending an extra 30 bucks to not have to do it again is worthwhile to me.

    Just wanted to post what I had found and it has successfully fixed my truck. Likely would not have found this without smoking the system as could not see the crack in the valve until it was removed from the gas tank, but found the problem quickly and allowed for a one time effort to fix the issue.

    Picture2.jpg
     
    Last edited: Dec 15, 2014
To Top