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Any harm in driving with P0441 and P0455 check engine codes?

Discussion in 'Gen 3 Prius Main Forum' started by Johnny Cakes, Aug 23, 2018.

  1. Johnny Cakes

    Johnny Cakes Senior Member

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    After about a year of ownership, my 2015 has the check engine light and P0441 and P0455 codes. I did a search in this forum and have learned from various threads that this is somewhat common.

    I purchased an OEM gas cap, but that didn't help.

    I can clear the code, but it comes back after a couple of days. Unless things get worse, I will be able to get through my state's vehicle check (which requires no check engine light to be on) by resetting it before I go.

    Main question: Is there any harm in driving the car with whatever faults that probably triggered these codes?

    Bonus points: Are there any other easy DIY fixes (besides the OEM gas cap) I should be trying?
     
  2. bisco

    bisco cookie crumbler

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    how many miles on her?

    did you buy new?

    how many times have you started and stopped the car since replacing the cap?

    have you ever overfilled the gas?
     
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  3. Raytheeagle

    Raytheeagle Senior Member

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    If you changed the gas cap, it’s probably in the evap system:(.

    It usually is a gross leak, with the usual suspect the gas cap. But if overfilled and into the evap canister / system, all bets are off.

    Good luck and keep us posted (y).
     
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  4. Johnny Cakes

    Johnny Cakes Senior Member

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    Thanks for the replies -- purchased used January 2017 with about 22K miles. It now has almost 50K.

    Overfilling -- I usually "top off" after the first auto shut-off of the nozzle at the gas station and squeeze some more in. OTOH, I've never gotten close to the point where gas splashes out or anything. I did let my daughter drive it this summer so I should probably ask her if that's an important clue.

    I cleared the code twice before replacing the cap. Since I replaced the cap, I've only cleared the code once (maybe twice). The tank has been filled with the new cap on. Started/stopped the car with the new cap, probably five times. Any chance this just goes away over time?

    It's my understanding that mostly "check engine" is emissions related -- is it fair to say that I will not do any damage to the car from driving it with these codes?
     
  5. Raytheeagle

    Raytheeagle Senior Member

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    The car won’t run as efficient and out of spec while the issue persists ;).

    But the check engine light is emissions component related (y).
     
  6. Grit

    Grit Senior Member

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    I drove a 98 camry that had a P0441 code for many years. Would turn of CEL drive for highway, drive til monitors were back online w/o CEL then quickly take to smog check and passed.

    There could be a leak from loose one end on/in the line carrying fumes to the evap canister, or fuel was topped off enough to where the gas is now in the canister itself and clogged. Also could be one of the lines to the canister maybe clogged with charcol and just need to be evacuated.
     
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