1. Attachments are working again! Check out this thread for more details and to report any other bugs.

P0401 Check Engine Light

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Zoddy, May 4, 2018.

  1. Zoddy

    Zoddy New Member

    Joined:
    May 4, 2018
    1
    1
    0
    Location:
    Pk
    Vehicle:
    2010 Prius
    Model:
    N/A
    Hi - I have prius 2010 98000 driven. I had P0401 with check engine light. Got Egr cleaned along with pipes, throttle body n MAP sensor. I didnt clean the intake manifold after opening, but client the passage it has to egr. Now the light is back almost about after 100k. What next should be done?
     
    #1 Zoddy, May 4, 2018
    Last edited by a moderator: May 4, 2018
    Prius_Angie likes this.
  2. Bay Stater

    Bay Stater Senior Member

    Joined:
    Mar 3, 2016
    534
    771
    0
    Location:
    Central Mass
    Vehicle:
    2013 Prius
    Model:
    Four
    You should clean the intake manifold too. There are four small return secondary ports that can clogged up with grime.

    Additional questions:
    Does your engine consume oil?
    Was the PCV valve replaced?
    You mentioned EGR cleaned. Does it include the EGR cooler?
     
    #2 Bay Stater, May 4, 2018
    Prius_Angie and Raytheeagle like this.
  3. RightOnTime

    RightOnTime Senior Member

    Joined:
    Sep 21, 2012
    745
    1,614
    183
    Location:
    Kidnapped in OC, CA
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    Original 12v battery?
     
    #3 RightOnTime, May 5, 2018
  4. NutzAboutBolts

    NutzAboutBolts Senior Member

    Joined:
    Mar 5, 2013
    1,476
    1,551
    0
    Location:
    Bay Area
    Vehicle:
    2012 Prius
    Model:
    Four
    You need to clean the whole egr system. It’s probably clogged with carbon. I would clean the egr cooler, pipe and intake manifold. If you cleaned it once before with the code and it went away, and now it has return, it’s probably has a build up of carbon over time.
     
    #4 NutzAboutBolts, May 5, 2018
    Prius_Angie, Bay Stater, Raytheeagle and 1 other person like this.
  5. orenji

    orenji Senior Member

    Joined:
    Aug 17, 2013
    5,884
    3,486
    0
    Vehicle:
    2010 Prius
    Model:
    Three
    EGR valve been replaced? If not its covered by Toyota for 15 years or 150,000 miles.
     
    #5 orenji, May 5, 2018
    Prius_Angie and Bay Stater like this.
  6. Raytheeagle

    Raytheeagle Senior Member

    Joined:
    Jul 1, 2016
    11,251
    15,476
    0
    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    While the valve is covered, that replacement won’t solve the underlying cause:(.

    Stories here point to the valve getting replaced, but everything else in the circuit being left “as-is”;).

    Cleaning the circuit is the best solution for the symptom (y).
     
    #6 Raytheeagle, May 5, 2018
    Prius_Angie, m.wynn, Bay Stater and 1 other person like this.
(You must log in or sign up to post here.)