P0421 / P0431 Trouble Codes (Catalytic Converter) ... anyone have good fix? | Page 7 | FerrariChat

P0421 / P0431 Trouble Codes (Catalytic Converter) ... anyone have good fix?

Discussion in '360/430' started by bisel, May 25, 2017.

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  1. G. Pepper

    G. Pepper Three Time F1 World Champ
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    #151 G. Pepper, Mar 7, 2018
    Cats checked out, BOTH PAIRS. Engine has new main seals, new head gaskets, new lifters, and new coils. It's running like a Swiss watch.

    Tell me about the air pump. I have O2 sensors on my list if tonight's reset doesn't do the trick, but I've never heard of the air pump issue.
     
  2. bisel

    bisel Formula 3
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    #152 bisel, Mar 7, 2018
    As I understand it, the purpose of the air pump is to inject air into the exhaust stream to allow for a fuller combustion of exhaust gases. On the Ferrari 360, each exhaust header has a hollow tube running along the side. The air pump injects air into the tube (called a rail), which injects the air into the exhaust manifold just downstream of the engine's exhaust valves.

    When you first start your car and the engine is cold, the ECU will enrich the fuel mixture for the cold start. The result is your engine runs better with a rich mixture when it is cold, however, there are un-burned hydrocarbons in the exhaust gas. By injecting additional air into the exhaust gases, these hydrocarbons will burn off in the exhaust manifold / header. The desired result is to burn off the unspent fuel -- reducing emissions -- and provide additional heat to get the catalytic converters warmed up quicker.

    When you first start your car on a cold morning, if you have an air pump, you will likely have noticed that your car is significantly louder for the first minute or so. Once your car warms up, the air pump should shut off at the time the ECU leans out the fuel mixture.

    If your air pump is not working properly, then on cold starts the fuel mixture will be rich, however no additional oxygen is available to burn it off. This rich fuel mixture will be making its way to your catalytic converters -- and they do not like a rich fuel mixture. This could trigger the codes.

    Regards,

    Steve
     
  3. G. Pepper

    G. Pepper Three Time F1 World Champ
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    #153 G. Pepper, Mar 7, 2018
    Thanks. My valved exhaust starts out loud due to the rich mixture, and goes quiet after a couple of minutes, so I don't think that's the problem.

    In any event, the car is off and I'll start it up tomorrow and see what happens. Let it idle 10 minutes, and then the drive routine. I'll let you know!
     
  4. ferralc

    ferralc Formula 3
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    #154 ferralc, Mar 9, 2018
    So? Update?


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  5. G. Pepper

    G. Pepper Three Time F1 World Champ
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    #155 G. Pepper, Mar 9, 2018
    I was just sitting down to post the update.

    Car was off for about twenty hours. Initially started up on only a couple of cylinders. A quick off/restart and it came up perfectly. Let it idle exactly ten minutes, and took it for a drive (Literally impossible to do the suggested run-in as my neighborhood is, well, a neighborhood). So I got on a limited access highway after about five miles, and did steady state driving for about 30 minutes, and stopped at my favorite cigar shop/liquor store. Drove back home the same route and no CEL.

    Next time I drove it, the CEL came back about ten minutes into the drive. So I'm going to swap out the O2 sensors now.
     
  6. ferralc

    ferralc Formula 3
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    #156 ferralc, Mar 9, 2018
    But what codes did you get? 421 and 431? Because if you have both swapping sensors will not make a difference


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  7. cpep

    cpep Formula Junior

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    #157 cpep, Mar 9, 2018
    Probably a bad sensor or a bad wire on a sensor from when it was removed. You could also check the fuses. Doubtful that it would be that but you never know. There is a fuse for each side behind each of the seats. Top left fuse in the fuse blocks.
     
  8. G. Pepper

    G. Pepper Three Time F1 World Champ
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    #158 G. Pepper, Mar 9, 2018
    How would I know? I don't have a diagnostic tool.
     
  9. bisel

    bisel Formula 3
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    #159 bisel, Mar 9, 2018
    The P0421 and P0431 are generic codes and are common across all cars. Take it to any auto parts store and they will read it for you.

    Steve
     
  10. ferralc

    ferralc Formula 3
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    #160 ferralc, Mar 9, 2018
    You can borrow one at an autozone or similar. I would do that prior swapping sensors
    Maybe you have a completely different issue


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  11. cpep

    cpep Formula Junior

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    #161 cpep, Mar 9, 2018
  12. G. Pepper

    G. Pepper Three Time F1 World Champ
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    #162 G. Pepper, Mar 9, 2018
    I'd like to buy one, actually, but I figured they'd be prohibitively expensive.

    The first CEL was read by Jim and he didn't give me numbers. One was an out of range error for the cats, the other was a low temperature warning (Those sound like the same thing to me, but whatever). We changed the cats, and the car was good for several drives over a week or so, then it came back. That's when I figured out what you guys were talking about with the OFF switch in the trunk. So I tried that, and the CEL came back after about 25 miles of driving, all on the same day.

    I guess it's possible they aren't the same codes, but I'd bet they are.
     
  13. ferralc

    ferralc Formula 3
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    #163 ferralc, Mar 9, 2018
    If I were you I would get the WiFi adapter I posted from amazon $20 and buy the EOBD facile app $15
    The free version can read codes but it doesn’t let you delete them



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  14. G. Pepper

    G. Pepper Three Time F1 World Champ
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    #164 G. Pepper, Mar 9, 2018
    That sounds like something I should definitely have on my iPhone... considering recent developments. :)

    BTW, just a note, but the engine has been restored with new main seals, new head gaskets, some new lifters, new coils (just a week or so ago), new fuel pumps...

    You get the idea. The places to look for problems become fewer and fewer. The headers were replaced, the cats were replaced twice, and the Capristo that came with the car was replaced with an NOS valved Challenge Stradale exhaust. If it is throwing ANY exhaust related codes, it's not the car's fault. Deduction leads me to the O2 sensors. If they are original, then they're eighteen years old and need to be replaced anyway. If they've been replaced before, then I should probably do it again.
     
  15. bisel

    bisel Formula 3
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    #165 bisel, Mar 9, 2018
    I agree with you. But may want to try Big Daddies mini cats first. Less costly than O2 sensors.

    Original Bosch sensors are PN 16196 for the downstream sensor and PN 17001 for the upstream sensors. If shop online, you should be able to get a set of four about $400 to $500.

    Steve
     
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  16. bisel

    bisel Formula 3
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    #166 bisel, Mar 15, 2018
    It appears I was premature with my assessment that the mini-cats have resolved the CELs. Today, got the dreaded CEL again. Feralc might very well have the best answer to all of this. That is, the position of the downstream sensor is a key component.

    Steve
     
  17. ar4me

    ar4me F1 Rookie
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    #167 ar4me, Mar 15, 2018
    Have you observed status of readiness monitors and pending codes along the way? May give you a quicker preliminary assessment whether your attempts are "working".
     
  18. bisel

    bisel Formula 3
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    #168 bisel, Mar 15, 2018
    I did not. Since installing the O2 extenders / mini-cats, it took longer before I got the CELs again. Maybe those efforts delayed the triggering of the CEL a bit. I cleared the codes last night. I think I will turn off the battery overnight to perform a complete adaptive parameter reset as well and then give it another go. Another F-chatter, Feralc, speculated that the position of the downstream O2 sensor could be complicit in all this. On the stock cats, the position of the O2 sensor is about mid-way on the cat. Therefore, this sensor is not getting the benefit of about half of the catalytic converter. He believes that the replacement of the stock cat with after market cats provides a position for the O2 sensor that is completely downstream of the all of the catalytic converter vs. just 50% of it. His hypothesis seems to make some sense. I am going to get a right angle O2 extender that will clear the obstruction I noted earlier and extend the O2 sensor a bit more to see if that helps.

    Steve
     
  19. ferralc

    ferralc Formula 3
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    #169 ferralc, Mar 15, 2018
    Steve try now the overnight reset as last resort
    It worked for me
    I have the Fabspeed mini cats though not the big daddies that apparently have more “honeycomb material” inside



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  20. ferralc

    ferralc Formula 3
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    #170 ferralc, Mar 15, 2018
    Well I can’t take credit for that, a former employer of Fabspeed named Evan is the one who wrote it here
    https://www.ferrarichat.com/forum/threads/fabspeed-motorsport-ferrari-360-430-sport-headers.470722/page-2
    Post #26
    And in my experience that is what happened because when I replaced my OEM cats with High flow cats my mechanic checked emissions, he said he was pretty sure it would not have triggered any CEL even without the mini cats, but he installed them anyways just to be safe.


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  21. gobuffs2002

    gobuffs2002 Karting

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    #171 gobuffs2002, Mar 15, 2018
    Steve, I'm sorry to hear about your CEL issues. One thing that I did was the get the ECU's reprogrammed by Ferrari. Those were the ECU's that came with the CS Exhaust system. I'm not sure how Ferrari reprogrammed the ECU's but it might of made a difference on my 2002 360 Modena. I have not had a CEL code since I installed the Fabspeed mini cats. Unlike everyone else, I have not had to do any resets on the ECU's after the initial install of the Fabspeed mini cats)

    I have 2002 360 Modena F1, 50k Miles with:
    Fabspeed Headers
    Hyperflow cats
    Ferrari CS Exhaust (using the New ECU's reprogrammed by Ferrari, CS Exhaust O2 sensors). I have been told that the CS O2 sensors are not as sensitive as the normal US O2 sensors. ( https://www.ricambiamerica.com/199612-front-lambda-feeler-not-for.html )
    Fabspeed Mini cats (the fat ones)
    Your Exhaust valve bypass controller (hard wired)
     
  22. bisel

    bisel Formula 3
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    #172 bisel, Mar 15, 2018
    My next step in all of this is to install a pair of right angle O2 adapters and two additional extenders Will also be performing overnight reset

    If that does not work I do have two additional ECUs in my storage cabinet that came with my Ferrari racing exhaust I never installed those bad boys yet

    I want to avoid replacing the cats because those guys cost A lot more than trying the above first

    Steve
     
  23. JoeTSI

    JoeTSI Formula 3
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    #173 JoeTSI, Mar 15, 2018
    The CS O2 sensors would likely do nothing for him since they would still show out of range by the ECU's. You're new reprogrammed ECU's are most likely the key, along with the CS O2 sensors.
     
  24. bisel

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    #174 bisel, Mar 18, 2018
    Last edited: Mar 18, 2018
    The saga continues ...

    I purchased two of each of these ... a right-angle adapter and an O2 extender ...

    Image Unavailable, Please Login

    And installed them this morning ...

    Image Unavailable, Please Login

    My hope is that with the extra length the O2 extender is giving me, perhaps that will make a difference. I turned the battery switch off for an extended period and am planning on doing the drive reset cycle later today. Hopefully, this will work. Not too much money spent so far, just a lot of time. If this fails to resolve the issue then will try new O2 sensors and perhaps putting in the pair ECUs I received when I got my Ferrari Racing Exhaust.

    Keeping my fingers crossed.

    Steve
     
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  25. whatheheck

    whatheheck F1 Rookie
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    #175 whatheheck, Mar 18, 2018
    Thanks for the updates Steve.

    I know how frustrating it is to have issues and try to resolve issues so I feel for you......

    I hope you get this resolved very soon. I know you've spent enough time on this.....

    Wishing you always the best.

    Dan
     
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