Chasing a P0301 code

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by MichaelB126, Jun 17, 2026 at 8:47 AM.

  1. MichaelB126

    MichaelB126 Junior Member

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    I've been chasing this for a while. Previously, recently changed maf sensor, fuel injectors( beck arnley), and catalytic converter. Separate unrelated issue, dash cluster not working, i think its the known capacitor issue prius' have.

    On way to work this morning, while driving car shutters. Check engine light was on then flashing. Checked on Dr prius app. Said P0301. Reset code. Shuttering continues.
    Any guidance is greatly appreciated. Im stuck. Thanks
     
    #1 MichaelB126, Jun 17, 2026 at 8:47 AM
  2. JC91006

    JC91006 Senior Member

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    If you have a code P0301 and you reset the code. It does not magically fix itself. You need to dig deeper to see what's causing that code and change the necessary parts to correct it
     
    #2 JC91006, Jun 17, 2026 at 11:15 AM
  3. MichaelB126

    MichaelB126 Junior Member

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    I understand. Any thoughts on what else I could look at?
     
    #3 MichaelB126, Jun 17, 2026 at 11:25 AM
  4. Mendel Leisk

    Mendel Leisk MMX GEN III

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    Google's AI is telling me a flashing check engine light is more urgent, and to stop driving immediately.

    Just editorial: it's "shuddering", not "shuttering". :)
     
    #4 Mendel Leisk, Jun 17, 2026 at 11:53 AM
  5. JC91006

    JC91006 Senior Member

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    Last time I encountered a flashing check engine light, the problem was a broken spark plug. You should check cylinder 1 on your car
     
    #5 JC91006, Jun 17, 2026 at 1:10 PM
  6. PriusCamper

    PriusCamper Senior Member

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    Move your ignition coils around to see if location of code changes... That's most likely the problem. Either that or you're two quarts low on motor oil.
     
    #6 PriusCamper, Jun 17, 2026 at 1:52 PM
  7. MichaelB126

    MichaelB126 Junior Member

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    Update.. I found the issue by accident, after I replaced the coil packs and spark plugs. It was the electrical connector at the fuel injector. There is an orange o ring wiper, and that was mashed down in the bottom of the connector. The orange didnt allow the connector to be fully seated, and I only was able to see it because of the low angle of the early morning sun. I attached pics of the wiper, after I dug it out with a micro pick set. The inner white part (of the connector) was able to come out with a small amount of prying, then I was able to get some room to dig out the orange from the bottom and back in place around the white and not behind it. Hope this helps the next guy.
     

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    #7 MichaelB126, Jun 20, 2026 at 8:49 PM
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