Acid bath and P0420

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by sorka, Jun 7, 2016.

  1. JC91006

    JC91006 Senior Member

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    well you're good for 2 years

    I got all my chemicals today to do this. Bought citric and oxalic acid in powder form.
     
  2. sorka

    sorka Active Member

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    At least on needing to smog it. In two years, I'll have another 75K miles on it (300K). I wouldn't be surprised if I have to deal with the traction battery by then.

    I also wouldn't be surprised if the P0420 returns before then as well.
     
  3. sorka

    sorka Active Member

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    This is the container I used. It's narrow and tall which is why I was able to get away with 8 gallons.

    [​IMG]
     
  4. JC91006

    JC91006 Senior Member

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    I would think 8 gallons would fill that all the way up to the top
     
  5. sorka

    sorka Active Member

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    About a third of the way. I guess I should have taken the shot with something for scale.
     
  6. sorka

    sorka Active Member

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    I take it back. It's about 1/2 way. Also, a 5 gallon painters buck *might* be tall enough to do it but just barely. I had hadn't thought about that because the container I had was black and I knew it would keep the water warm in the sun.
     
  7. JC91006

    JC91006 Senior Member

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    did you have to wear gloves for this project?
     
  8. sorka

    sorka Active Member

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    I did. I think it's a good idea. I also wore eye protection on the off chance anything splashed in my face.
     
  9. sorka

    sorka Active Member

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    Well drat. I got the P0420 again. It lasted about 3K miles.

    Possibilities:

    1) The acid bath did nothing it was the actual washing it clean that allowed it to work well enough for a while. I'm going to repeat this in about 2 years to see if I get the same result just from cleaning.

    2) The acid bath worked a little but since i wasn't running the water continuously nor did I have it at the 150F that the study cited, I didn't get anywhere near the surface etching required to remove the contaminant metals. It could very well be that it worked well enough for what I did that it was on the threshold of throwing the code over the last 3K miles but squeaked by. I reset the code 200 miles ago and it hasn't returned, so if I get another couple thousand miles out of it again doing nothing, then I'll assume that the acid cleaning worked but that I didn't do it as completely as I should have having skipped steps and conditions cited in the study.

    3) A combination of both 1 and 2.
     
  10. JC91006

    JC91006 Senior Member

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    At least you got your smog check done last week
     
  11. sorka

    sorka Active Member

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    OK, another 500 miles since getting the P0420 and it hasn't returned yet. This leads me to believe that the original bath restored the cat to a barely sufficient efficiency level. For sure next time I'll be doing the full treatment at the correct temperature and flow rather than just having it sit. I did stir it every 30 minutes or so but that's not the same as constant flow. And 120F is not the same as 150F.

    Got my sticker yesterday in the mail :)
     
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  12. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I'm wondering how you would maintain 150 degrees F for an extended period, considering the relatively tonic nature of the acid bath.
     
  13. jichi

    jichi Junior Member

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    I am having the same problem it just happened after I changed my spark plug and I broke ceramic piece from spark plug number four and did not know it until I drove the car start getting misfire then got that taking care of. The next day I start getting Misfire again and P420. I found that my wiring got lose inside near the cabin filter fixed that no more misfire then now get P420.

    MY question is can you check the temperature for Bank 1 sensor 1 and bank 1 sensor 2(before and after cat coverter O2 sensor). I mine is showing the following

    IMG-20160712-WA0000.jpg

    As you can see Bank 1 sensor 1 showing 1080F Bank 1 sensor 2 showing 859.
    I read on the internet Bank 1 sensor 1 temperature should be less than Bank 1 sensor 2. if not then you got restricted cat.
    I am not sure if you have to have the custom PIDs with full version of Torque in order to see these parameters.

    I would really appreciate your input. Thanks
     
  14. MattStevenson

    MattStevenson Member

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    I got away with just putting in an O2 sensor spacer years ago. That was in TN though and the testing facility isn't owned by the government so I wasn't worried about getting a ticket or anything.

    Posted via the PriusChat mobile app.
     
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  15. SFO

    SFO Senior Member

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    Any updates?
     
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