Help with p0446 p0496 codes

Discussion in 'General Chevy & GM Tech Questions' started by cobray, Feb 7, 2012.

  1. cobray

    cobray New Member

    I have a '05 Tahoe. I noticed a strong gas smell in the car. seems to be tward the rear. I have p0446 p0496 codes. it is sometimes difficult to first start up.
    From what i have read it may be an issue with the EVAP canister vent valve or EVAP purge valve located on the intake manifold.

    I thought I would first replace the EVAP purge valve since it is low cost and easy to change.
    I can't find the one that I have. All the ones I see on the web and at the Autozone are not the same.
    I am not sure where to find one.
    i may not even be the EVAP purge valve anyway.
    Any ideas?

  2. FrigginNoodles

    FrigginNoodles Epic Member 5+ Years 500 Posts

    I had a similar problem where my truck was throwing the p0446 code and one other (can't remember sorry). I am not a mechanic by any means so forgive my seemingly screwy wording and if you don't understand some of this let me know and I will do my best to help you out.

    It was my Fuel Vent Solenoid.

    The reason you can't find the part, or that is looks different, it because the replacement is different. What happens is that the Fuel Vent Solenoid becomes clogged with dirt and dust. This in turn will stop the gas tank from venting fumes properly. Which is probably why you can smell fuel. For me it became so bad that I could hardly pump gas. I would have to go fifty cents, then wait for it to settle, another fifty cents, wait more, etc.... It really sucked!

    The new one should be a two piece set up that will replace the current one piece set up. If you crawl underneath your Tahoe the part is located near the rear of the gas tank. It looks like a black plastic can with a rubber hose and an electrical plug on it. When I changed mine I sliced the hose of and.... whoosh I could here the trapped air immediately escaping. I have some links saved on my other computer for some articles that will help you find and replace the part. I will update in a minute or two.

    **EDIT** You may have to do some more digging around but hopefully these will help. The third link has some good pictures explaining where everything is located and how to do the install. I was overwhelmed at first and almost took it to the dealer, but it is truly an easy fix. And like I said above, just let me know if I can help you out more.

    LINK 1
    LINK 2
    LINK 3

    Last edited: Feb 7, 2012
  3. cobray

    cobray New Member

    Thanks for all the info. What tear was yours?
    Looks like around a $100 part. Is that right?
    Do you need to jack it up a bit to get to it?
    Thinking it is this one and not the Solenoid on the intake manifold.
    thanks again!

    ---------- Post added at 07:56 PM ---------- Previous post was at 07:52 PM ----------

    Sorry...meant what year is yours.
    Also, Did you have to Raise the transmission and reinstall the transmission support?

  4. FrigginNoodles

    FrigginNoodles Epic Member 5+ Years 500 Posts

    1. I have a 2007 Silverado Classic, so it's very similar to the 03-06 Chevys'. The write ups and diagnoses I found to use was for the 03-06.

    2. I purchased the part on Amazon, I believe I paid around $70 for it.

    3. I was able to climb underneath it okay. It was a bit tight, but I am pretty slender and limber.

    4. I didn't have to mess the the transmission or the support.

    The old "bucket looking" solenoid has a clip that slides into a bracket mounted on the frame. With the replacement part, it will mount on the same clip by sliding it on the same way the old one came off, and the other new part can be attatched anywhere you like via a zip tie. You will need a short length of hose that isn't included with the new kit. The hose is simply used to connect the two new pieces together. I purchased two feet of 5/8" radiator hose from NAPA for a few bucks. I'll run out and get a few pics to give you a better idea of what it looks like. Ill have them up in a few.
  5. cobray

    cobray New Member

    Thanks so much for your help!!

    ---------- Post added at 09:05 PM ---------- Previous post was at 08:34 PM ----------

    One last question, did you also replace the Canister Assembly too ?

  6. FrigginNoodles

    FrigginNoodles Epic Member 5+ Years 500 Posts

    I only used the kit and did not replace the canister assembly.
  7. cobray

    cobray New Member

    well i put in the Fuel Vent Solenoid 2pc kit. .....still smell gas! replaced the gas cap..still smell gas!
    I give up!
    Any ideas??
    Thanks for all the help.

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