Hello. First timer here. Old timer everywhere else!

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by CJK, Jun 20, 2026 at 4:48 PM.

  1. CJK

    CJK New Member

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    Location:
    Phoenix
    Vehicle:
    2010 Prius
    Model:
    ----USA----
    2010 with 142K. Vehicle was working perfectly and the check engine light came on. Code was P0401. EGR valve and gaskets. I bought the kit from PartsGeek. My mechanic changed it but didnt do the other steps, ie; cleaning cooler, pipes, intake manifold etc... I drove a few miles and my gas pedal went limp, car knocked a few times as I turned into a pkg lot and turned off the engine. I did start it again and made it home, 14 miles.
    I've been reading, watching and researching and I told mechanic about after market parts being not read by the ECM and cleaning the carbons from the system ....he took the plug off of old EGR and put it on new one....that fixed the ECM deal. Now my mechanic wants to clean my cats!!!! Wth? Would that even help? Shouldn't he clean the parts of the EGR system FIRST? I bought 4 cans of the stuff that is safe for aluminum and plastic.....and I have already paid quite handsomely for the repair in the first place.
    Im in Phoenix if anyone has a good, trustworthy mechanic in the area.
    Thank you for any response. Be well.
     
    #1 CJK, Jun 20, 2026 at 4:48 PM
  2. CR94

    CR94 Senior Member

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    Vehicle:
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    Two
    You bought an aftermarket EGR valve? According to what I read here (having no personal experience), those usually don't work. Yes, the EGR tract (cooler, valve, pipes, intake manifold ports) should be cleaned out, if clogged. There are numerous threads about that in this site.

    Be skeptical of claims to clean a catalytic converter, if that's what he was trying to say..
     
    #2 CR94, Jun 21, 2026 at 2:25 PM
    Alexikor and Brian1954 like this.
  3. Alexikor

    Alexikor Junior Member

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    Location:
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    Vehicle:
    2010 Prius
    Model:
    II
    i've been to two mechanics in phoenix, and their hourly rates were no less than the dealership's labor rates. one was TMC Auto Repair in Tempe and the mechanic's name was Martin. He seemed liked a honest person as he didn't try to invent problems, but ultimately was uninterested in trying to diagnose my issue, and i forgot the other mechanic.
     
    #3 Alexikor, Jun 21, 2026 at 9:57 PM
  4. Mendel Leisk

    Mendel Leisk MMX GEN III

    Joined:
    Oct 17, 2010
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    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Maybe just try cleaning your existing EGR valve?
     
    #4 Mendel Leisk, Jun 22, 2026 at 10:28 AM
    CR94 likes this.
  5. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
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    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    First, finish the story. How does it run now? Rattling on startup? Low coolant reservoir? Limp mode or low power? Codes and which codes?

    You can't clean a catalytic converter. If its so clogged that it is causing low power and stalls you need a new one. There are ways to measure pressures in front of the cat to determine if its bad. However a clogged cat does not go away and allow the car to sometimes run right.

    A clogged egr cooler or pipe will not cause low power or stalling. In fact mechanically blocking it is a diagnostic method to determine if your aftermarket valve is sticking open - which is common and can cause rough low speed engine operation.

    No cost egr block flow test. If the rough running goes away you are a victim of a sticking aftermarker egr valve.


    IMG_1897.jpeg IMG_1898.jpeg


    Updated Oem egr Kit. 04004-58137 with proper housing number
    IMG_1899.jpeg
    Newer EGR Valve is 25620-37120

    Egr valve updated Kit 04004-58137
    and includes 25620-37120 Updated egr valve - plus is lower cost than valve alone.
     
    #5 rjparker, Jun 22, 2026 at 10:55 AM
    Last edited: Jun 22, 2026 at 11:34 AM
  6. rjparker

    rjparker Tu Humilde Sirviente

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    By the way the $129 partsgeek valve is aftermarket.

    Oem from online Toyota dealer
    IMG_1900.jpeg IMG_1901.jpeg
     
    #6 rjparker, Jun 22, 2026 at 11:30 AM
  7. Alexikor

    Alexikor Junior Member

    Joined:
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    Location:
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    Vehicle:
    2010 Prius
    Model:
    II
    if you order from the camelback toyota (search parts.camelback toyota) you can pick it up at the parts desk and avoid paying shipping/porch pirates
     
    #7 Alexikor, Jun 22, 2026 at 1:17 PM
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