2016 Prius Check Engine Light – P0456 Code

Discussion in 'Gen 4 Prius Care, Maintenance and Troubleshooting' started by Alyssa L, Feb 25, 2026 at 5:19 AM.

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  1. Alyssa L

    Alyssa L New Member

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    Hi everyone,

    My 2016 Prius just showed a check engine light. The car seems to run fine.

    I scanned it with my Autel MK808Z and got P0456 (EVAP small leak detected).

    Has anyone dealt with this before?
    Should I start with the gas cap or check something else first?

    Any advice would be appreciated. Thanks!
     
    #1 Alyssa L, Feb 25, 2026 at 5:19 AM
  2. BiomedO1

    BiomedO1 Senior Member

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    Yep; start with the gas cap and inspect the lip of the fill tube. Any nicks or cut to the gas cap gasket or tube lip can cause a leak.

    Good Luck...
     
    #2 BiomedO1, Mar 2, 2026 at 9:08 PM
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