Cataclean and EGR Clog Codes

Discussion in 'Gen 3 Prius Technical Discussion' started by C-in-DC, Feb 21, 2023.

  1. ChapmanF

    ChapmanF Senior Member

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    What app is that? I can't even tell what tests those results are for.... (The second one, I see, refers to test ID 8E ... but I have to admit I have slacked off on memorizing my hexadecimal test IDs ....)
     
  2. C-in-DC

    C-in-DC Member

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    I’m assuming this is 6 for egr monitoring.
     
  3. C-in-DC

    C-in-DC Member

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    I think you said obdII function 6 was the way to test if the egr is working. The egr I bought online last year was a fake. I bought an oem replacement later on and installed it. It’s been about 40,000 since then so I figured now is a good time to change the coolant and clean the egr
     
  4. C-in-DC

    C-in-DC Member

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    I’m using a thinkcar thinkdiag.
     
  5. ChapmanF

    ChapmanF Senior Member

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    The car does lots of self-tests ("noncontinuous monitors") on lots of things, EGR being one of the things. OBD-II mode 6 is the way to look at the test results for all those things. Each family of tests has a module id, and each test within a module has a test id. EGR Monitor, Bank 1 is module ID 31 (hexadecimal) and test ID bd. It will be reported in units of pressure (often kilopascals, though some scan tools will show psi). Catalyst tests, I think, are MID 21 or 22 (hex) and I'm not sure of the TIDs. I think the test result unit for the catalyst O₂ Storage Capacity test should be time (seconds).

    Those screenshots you're showing, neither one shows a module ID, one shows a test ID that I don't think I recognize, and they both seem to be reporting results in volts. I just don't know what tests those are.
     
  6. C-in-DC

    C-in-DC Member

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    thanks.
    This scan tool app is reading diff on an iPhone. Gotta get my old Samsung and post the results from there.
     
  7. C-in-DC

    C-in-DC Member

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  8. ChapmanF

    ChapmanF Senior Member

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    Well, the very last one of those (EGR monitor test ID bd) is the only one I'm much familiar with, and 21.9 kilopascals is great, the sort of number normally seen right after a full cleaning.

    The other tests there, I can't really identify. I haven't memorized the hexadecimal test IDs for the most part.

    If the first one, catalyst monitor TID a9, is the oxygen storage capacity test, then it looks ok. But I'm not sure that's the test I'm thinking of.
     
  9. C-in-DC

    C-in-DC Member

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    I’m getting 18 mpg avg and 39 mpg consumption. I assumed the egr needed to be cleaned but i guess not. I’ll search other threads regarding mpg. I’m wondering if the cut jiggle pin and additional hole in the t-stat isn’t allowing the engine to get warm enough and in turn the egr valve isn’t opening. or I got drag from the wheel bearing I didn’t change last year.
     
  10. C-in-DC

    C-in-DC Member

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    Update: P0420 is back. I believe I’ve only driven 40,000 miles since magnaflow replacement was welded on. Can I complain? No! but I will. Also Will post obd readings soon.
     
  11. MAX2

    MAX2 Senior Member

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    It would be correct to look at the parameters recorded when this error code appeared.

    Non-original catalysts cost significantly less and their service life, as you can see, is also short.
     
  12. C-in-DC

    C-in-DC Member

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    Here are some screenshots from my
    Scan tool app. Looks like there’s insufficient flow so the cat got burned or maybe faulty gasket? AF sensor is reading about 40 degrees different from o2 sensor. I remember at one point @ChapmanF said something about the sensors reading at least 100 degrees or so different.

    I’m seeing a lot of carbon build up on the top of the engine. My oil change light has been on for about a week. I checked the oil level and it’s full(oil looks new). doesn’t appear to be burning any. I haven’t had any misfires and my coolant level is normal.
     

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  13. ChapmanF

    ChapmanF Senior Member

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    I don't think that could have been me. I don't know anything about interpreting those O₂ sensor temperature readings—other than that there is no temperature sensor either place, so they are estimates of some kind derived from something else, and both those sensors are heated, so the temperature estimates might be provided mostly for info on whether the heaters are working.

    I watched a silly youtube video one time by somebody who thought a temperature difference between inlet and outlet told you what you'd need to know about the cat. He was using an IR temperature gun to read cat temperatures from the outside, and the silliest part was he used one of those IR guns that shoots a little red laser dot in the center of its averaging area, and he thought because he could sneak that little red dot through a tiny chink between some heat shields and brackets and stuff, the temp showing on the tool was really the temp of the exact place his little dot was.
     
  14. C-in-DC

    C-in-DC Member

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    my apologies then. Memory is not what it used to be.

    whole lot of build up at the fuel injectors. Is that normal? Obvious leak? I see you posted a manual for troubleshooting this in another thread.
     

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  15. C-in-DC

    C-in-DC Member

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    This cat was $1,244 two years ago.

    I’m sure OEM is four times that now.
     
  16. ChapmanF

    ChapmanF Senior Member

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    Just dirt piling up on the engine around them? Well, they're in sort of recessed areas and engine compartments get dirty.

    Happily, it's not as if stuff building up around the outside of the injector affects what happens inside it.

    It is worth trying to blow out or clean up before removing an injector, so the dirt doesn't fall in the hole.