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Evap trouble codes P0441 and 0455.

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Markbratz, Aug 26, 2024 at 9:35 PM.

  1. Markbratz

    Markbratz New Member

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    Kalispell MT
    Vehicle:
    2015 Prius
    Model:
    Three
    Good evening. Long time lurker - first time poster!

    2015 Prius. Lots of miles. Car sat for 8 months. Shortly after starting to use again, we got the dreaded P0441 and 0455 codes recently. Tried the easy fix by replacing gas cap and reset - code comes back.

    I started by removing the air box and accessing the purge valve mounted to the air intake on the engine. I removed the valve and applied vacuum to the valve. It seems that valve is not leaking.

    However, when I blow into the hose that leads toward the tank, I can blow very very easily. Almost no resistance. My understanding is that the tank is a closed system, meaning that if I blow in the hose . . . it shouldn't go anywhere. Am I understanding that correctly? If so, would I be correct in assuming that there is a leak/crack/mouse chewed up spot/cut somewhere along that hose leading back to the fuel tank?

    I suppose the next step is to pull all of the "covers" off from around the fuel tank and look for anything obviously wrong with the hose.

    If I've got that all wrong, what steps might you suggest instead?

    Many thanks in advance for your thoughts, wisdom, and sarcasm (!).

    ~markbg
     
    #1 Markbratz, Aug 26, 2024 at 9:35 PM
  2. Tombukt2

    Tombukt2 Senior Member

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    Vehicle:
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    All the Toyota's I've had with this type system like my 2001 sienna the problems never been up under the hood it's always back in the back near that evap menagerie of crap in that rectangular formation that it's in there's one or two evap switches back there that get corroded and disgusting and stop working there's even YouTube videos of guys and third world countries breaking those switches apart cleaning them showing you the damage putting them back together and they work I believe in my sienna van that's what would put the light on that switch back there at the purge bank or container whatever that's called right above the tank in front of behind it whatever you want to call it I believe in the Prius it'll probably work out to be very similar If you go back there and look you'll see one or two of those electric valves but 12 volts to them see which one doesn't click break it open if you're so inclined and see the rust and nastiness clean it up and it'll work or the switches are like $13 online several manufacturers make them And my sienna when the check engine light came on I went back and replaced that valve or cleaned it and fixed it and the light went off.
     
    #2 Tombukt2, Aug 27, 2024 at 2:47 PM
  3. ASRDogman

    ASRDogman Senior Member

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    Vehicle:
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    #3 ASRDogman, Aug 27, 2024 at 4:14 PM
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