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Emissions check engine light

Discussion in 'Gen 3 Prius Technical Discussion' started by JeffAnd, Nov 27, 2023.

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  1. JeffAnd

    JeffAnd Junior Member

    Joined:
    Jul 19, 2021
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    Location:
    Wisconsin
    Vehicle:
    2004 Prius
    Model:
    ----USA----
    2014 prius has the following codes.
    P0171. Too lean bank 1.
    P0101. Range/performance problem of mass air flow circuit.
    P0446. Incorrect purge flow of evaporative emissions control system.
    P0455 gross leak of evaporative control system detected.
    I did a smoke test on the evac system. Leak was detected by the gas cap. New gas cap is on order. This should take care of the P0446 and P0455 codes. But will this cause the P0171 and P0101 codes. I did clean the Mass air flow sensor. This seemed to have no effect on the fuel trims.
     
    #1 JeffAnd, Nov 27, 2023
  2. BiomedO1

    BiomedO1 Senior Member

    Joined:
    Mar 27, 2021
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    Location:
    SacTown, Ca
    Vehicle:
    2021 Prius Prime
    Model:
    LE
    Check the engine air intake path & air filter. Look for wiring issues on the mass flow and O2 sensor wires. Check for holes in the intake hose leading to the intake manifold. If there isn't a chance of sucking something into your intake, you can disconnect at the air filter. Take it for a test drive to see if the mass flow error goes away. Your isolating blockages below your air filter.
     
    #2 BiomedO1, Nov 27, 2023
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