EVAP Purge Valve Issue

Discussion in 'Performance & Fuel' started by MWright936, Sep 19, 2010.

  1. MWright936

    MWright936 Epic Member 5+ Years 1000 Posts

    I posted a question about this a while back. Then, I was mainly looking to see if my issue would cause any bigger problems. Now, I want to fix it.

    My truck is throwing these two codes: P0449 and P0496

    Both of these codes have something to do with the EVAP system. I am not sure exactly what they refer to, but from my research, it appears to be the EVAP purge valve or EVAP purge solenoid.

    I have replaced the solenoid that is attached to the intake manifold under the hood. I have also replaced my gas cap to make sure it was making a good seal. The only other thing I can think of is to replace the purge valve that is mounted just in front of the fuel tank along the frame rail. Here is a photo:


    When I ordered my replacement solenoid, I thought I was ordering this part, but I was mistaken. Can anyone tell me a part number or maybe even a link to where I can order the part pictured above?

    I have tried taking it off and cleaning it, but that didn't help anything. There is something rattling when I shake it, which makes me believe this is the cause of my check engine light. Thanks in advance for any help!!
  2. silveradotrailblazer

    silveradotrailblazer Epic Member 5+ Years ROTM Winner 5000 Posts

    Yep, mine went bad a few years back and when I replaced it the guy at the dealership said to get some rubber fuel line and run the breather vent up to the front of the truck. I mounted the vent up near the brake booster. No more problems. Maybe some aftermarket companies like Dorman are making them now.

    ---------- Post added at 04:33 PM ---------- Previous post was at 04:23 PM ----------

    Nope dorman doesn't have one, but you can sign up for a FREE torque spec poster.
    ChevyFan likes this.
  3. TrailLeadr

    TrailLeadr Epic Member 5+ Years 1000 Posts

    I actually just had to replace mine about a month ago.
    If I recall properly it was about $28 from the dealer.

    Now be warned I've heard stories that for the silverado application these things run in the $1xx.00' of dollars where the Avalanche and suburban are much much cheaper. The part number is the same for either Silvy, Avalanche, or 'burb. So the price difference makes no sense to me. The part number is : 'GM# 25932571

    The vent valve typically goes bad over time due to dirt and dust but also if water intrudes into the canister or fuel backs up into it from constantly topping off the tank. So don't top off if you do.

    The canister can be easily opened and cleaned. You'll likely find that it's just dirty inside. You might even be able to reuse it after you clean it and save yourself the $$.After I replaced mine I took the old one apart and cleaned it out with hot water. I'm keeping it as a spare in case it's ever needed. Clean the black sponge inside with soapy water to get it nice and clean.

    Everyone says you need to replace the hose when you replace the vent valve because it's shrink tubing. I actually found that the clips are easy enough to release from the vent valve, so that you can just pop the new one in. Do be aware that if you do not replace the hose you should at least clean it as it will have a fair amount of dirt built up around the interior of the hose. A small bottle brush will work well for this. *edit: nevermind, I see from your pic that you don't have a clip from the hose to the vent valve. So you'll need to replace the hose.

    You'll need 5/8" heater hose and two hose clamps. the parts guys should already know this though.

    I'm kinda running out the door right now, so if I've left anything out please ask.
    Last edited: Sep 19, 2010
  4. MWright936

    MWright936 Epic Member 5+ Years 1000 Posts

    Are you SURE it is the same part? When I typed in that part number at GM Parts Direct, it came up with 'Fuel Tank Evaporator Control' for only $15. It doesn't specify year or model, so it makes me nervous to order it. It sounds right, and the price is right, I just want some verification. Hopefully that's the one, and I can finally get rid of that darn check engine light!!
  5. TrailLeadr

    TrailLeadr Epic Member 5+ Years 1000 Posts

    Sorry, I forgot to check this thread.

    Here's some pics of the one I took out of my avalanche:

    Dscf0051.jpg vent_top.jpg Dscf0053.jpg vent_connector.jpg Dscf0052.jpg

    Only numbers listed are PA-GF30 and the patent number:6599350 and CAV.K printed under the patent number.
    Last edited: Sep 24, 2010
  6. MWright936

    MWright936 Epic Member 5+ Years 1000 Posts

    Thanks!!! That's definitely a big help! I will compare the numbers on mine to see if they match for sure, but that looks just like it. Hopefully I can finally get that darn check engine light to turn off!
  7. TrailLeadr

    TrailLeadr Epic Member 5+ Years 1000 Posts

    Good luck, and keep us posted.:great:
  8. MWright936

    MWright936 Epic Member 5+ Years 1000 Posts

    I'll definitely update my findings on here. Is there any way I can re-use the hose that's attached to the unit I have, or will I have to get a new one? If I need a new one, is there an easy way to figure out that part number??
  9. TrailLeadr

    TrailLeadr Epic Member 5+ Years 1000 Posts

    They don't make a replacement hose. If your pic above is from your truck it looks like you'll need a new hose. The parts guy at Balise Chevrolet where I got mine said they go through these like crazy. According to him the hose is always replaced with a 5/8" heater hose and two hose clamps. So I ended up getting a hose at his recommendation anyway, but didn't need it.

    On my '06 the hose had a locking quick connect at the vent valve which allowed me to reuse it.

    I remember reading somewhere that someone had relocated theirs to under the hood because they drove on very dirty dusty roads. I can't help to wonder if this would have any negative impact on it's function or not. But it's something to think about.
  10. MWright936

    MWright936 Epic Member 5+ Years 1000 Posts

    I don't think just any hose would work for a replacement. It takes two 90 degree turns to come back into the side of the charcoal canister, so if I tried to use other hose, it would probably just kink. I guess I'll just order the part and see what happens. If it comes down to it, I guess I can consult the Chevy dealership in town, but I've heard they're crooked, so that's my last resort.

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