High Catalyst Temperature, Slow Down light with decat pipes | FerrariChat
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High Catalyst Temperature, Slow Down light with decat pipes

Discussion in 'Technical Q&A' started by bluesunday, May 24, 2021.

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  1. bluesunday

    bluesunday Karting

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    #1 bluesunday, May 24, 2021
    Hey,

    I have an interesting phenomenon that has developed a couple of days after installing an aftermarket exhaust.

    I have recently installed a full decat exhaust and a Novitec Techtronic - running smoothly without any CEL. Did a couple of days of extreme driving to enjoy the high-raving noise that I have missed ever since owning my F8.

    Today, I have visited a gas station running very low on fuel (~30km cruising range) and fuelled it up. Around 10km later, while on a highway, I have got a "High Catalyst Temperature, Slow Down" light on the dashboard.

    The exhaust itself wasn't warm whatsoever, as I wasn't driving it hard, especially compared to past few days. I have pulled over, shut it down, and continued driving. The light came up one more time, 300km later, again, this time a few minutes after cold start. Later, I did a bunch of 1/4 mile starts, came back to my town (~500km trip) and didn't have this light anymore. In the meantime, I have fuelled it up once again, this time on a different petrol station.

    Generally speaking, it seems to be mileage and pressure exclusive - it is not bound to the spirited driving and periodic ECU checks, otherwise I would be able to reproduce it.

    I am wondering what could the the cause for this light to appear periodically, especially that I am not running any cats? Is it a result of a poor batch of a fuel, leaks in the exhaust or something else? It only happened twice so far, but I am always keen to understand what's going on under the bonnet.
     
  2. Qavion

    Qavion F1 World Champ
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    #2 Qavion, May 24, 2021
    Perhaps the exhaust installer damaged the thermocouple wiring? Or perhaps a random failure?

    Do you know which side is triggering the SDL? Do you have an OBD2 reader?
     
  3. bluesunday

    bluesunday Karting

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    #3 bluesunday, May 25, 2021
    Haven't done the read out yet - kinda afraid to do it without Novitec module plugged in to avoid CEL in memory (unless there's a way to clear it in a way that there's no record).

    If the wiring was damaged, I would expect this to happen more frequently.
     
  4. Qavion

    Qavion F1 World Champ
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    #4 Qavion, May 25, 2021
    OBD2 readers usually offer a bulk erase function (all faults cleared).
     
  5. yelcab

    yelcab F1 World Champ
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    #5 yelcab, May 25, 2021
    Deleted
     
  6. Llenroc

    Llenroc F1 Veteran
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    #6 Llenroc, May 25, 2021
    I think it is a random failure as you said. There isn’t a thermocouple on the later Ferraris, the hot reading comes from the O2 sensors.
    I had this happen on my 458 a few years ago, no cats after market headers and exhaust, turned off engine restarted message has never come back.
     
  7. bluesunday

    bluesunday Karting

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    #7 bluesunday, Jun 3, 2021
    It just came up once again, this time at 4300 mileage. I am going to keep this thread updated for my future self, as I am working on resolving this. I am in touch with Novitec too, we will see if there's any update. I can say it's definitely not fuel and temperature related, as it seems to occur at random times.

    Sometimes I wish there were more Ferraris locally with modifications, it would be much easier to debug.
     
  8. bluesunday

    bluesunday Karting

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    #8 bluesunday, Jun 29, 2021
    Last edited: Jun 29, 2021
    Update:

    It kept coming up on the following intervals:
    4300 [slow down light]
    4700 [slow down light]
    4767 [check engine]
    5048 [slow down light]

    I have been issued a second copy of Novitec Techtronic which doesn't work either. The response from Novitec is that the error is not catalyst/GPF related and in fact, does not happen on their exhausts. I can confirm this, as a friend is running Novitec Stage 2 with Techtronic and has no issues whatsoever.

    They believe it is either a failed sensor or the exhaust design itself.

    The codes are:
    P0401 Exhaust EGR Flow Insufficient
    P1291 Injector High Side Short To GND Or VBATT (Bank 1)

    Does any of the aforementioned have to do with "SLOW DOWN, CATALYST TEMP. TOO HIGH"? I am afraid the codes are related to the Check Engine. I guess after all these are all related to the same issue, but I would really like to understand the root cause behind SDL.
     
  9. yelcab

    yelcab F1 World Champ
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    #9 yelcab, Jun 29, 2021
    This code: P1291 Injector High Side Short To GND Or VBATT (Bank 1), tells you that one of the fuel injectors on bank 1 is stuck on. Probably something to do with the wiring. If it is stuck on all the time, it would result in excess fuel and cat temperature too hot and the SDL coming on.
     
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  10. bluesunday

    bluesunday Karting

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    #10 bluesunday, Jun 29, 2021
    Last edited: Jun 29, 2021
    Interesting, how this could possibly happen? Random? I don't think that's where we touch while installing a new exhaust, right?

    If it was stuck all the time, I guess CEL would be on throughout the whole time. CEL happened only once, maybe it was a random kind of failure. But indeed, that would make sense.
     
  11. yelcab

    yelcab F1 World Champ
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    #11 yelcab, Jun 29, 2021
    In a normal exhaust with a cat, the excess fuel would burn up and cause the cat temperature to be very high. But there is no thermocouple to actually measure the temperature so we would have to surmise that the ECU is using the O2 sensor (or most likely a wideband sensor) to infer that there is excess fuel and its presence would cause high cat temp and therefore a SDL is thrown up.

    I can't say what was done while installing the exhaust so ... no guesses here. It's worth checking out the voltages on the injector while the car is running.
     
  12. bluesunday

    bluesunday Karting

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    #12 bluesunday, Jun 29, 2021
    Thanks for explanation. Maybe it's not related to the exhaust, maybe it's just a coincidence since the first time it happened was shortly after fueling up and a friend of mine that was travelling behind me said he saw a dark cloud coming out of the exhaust pipes for a second, like a diesel.

    We will definitely debug this route.
     
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  13. Themip

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    #13 Themip, May 30, 2022
    Did you ever get this sorted out? I just bought and had a Ryft exhaust (catback) exhaust installed with the novitec obd plug. No cel/check engine lights but almost every drive high cat temp slow down comes on. Drives just fine minus I notice when I downshift my vehicle doesn’t slow down it kinda revs itself up. How can I fix this?
     
  14. harrish1985

    harrish1985 Formula Junior
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    #14 harrish1985, Jun 8, 2022
    I too have this issue now with a CEL light. I only did Novitec valveless exhaust with techtronic on an F8. Any updates on your end?
     
  15. Themip

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    #15 Themip, Jun 9, 2022
    Ryft finally got back to me. They found an issue with the latest ferrari ecu update/software. Causing the car to run rich if you have an aftermarket exhaust. Ryft is shipping my car to their shop and redesigning the exhaust for me as they said they have fixed the issue by moving the bungs for the o2 sensors. Guess a few others have reported the same in the past couple weeks.
     
  16. harrish1985

    harrish1985 Formula Junior
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    #16 harrish1985, Jun 9, 2022
    hmm interesting did they provide details on the date the ECU software was done? Not sure if this is applicable to Novitec.
     
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  17. Themip

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    #17 Themip, Jun 9, 2022
    I literally know nothing else at this time just the general info they gave me. I did just buy my F8 almost 2 months ago from Rancho Mirage Ferrari so no idea what version ECU software I currently have. It was serviced the day i bought the vehicle. I have emailed the owner back asking if there is any more specific info as others are having the same issue even with Novitec exhausts. My brothers F8 has the same exhaust you have and he has 0 issues. His also hasnt been to the dealer in almost a year. Be interested to see if when he gets serviced if they do an ecu update and then he starts getting the issue. Only thing i know for sure is with the Ryft OBD i was getting the ECU system failure code every time i was driving the car, and with the Novitec OBD plugin i have only gotten that code a couple of times, more so often now when i get the cat overheating code error pop up. They informed me they have a new version 2 of their obd plug which will fix my cel code as well with the new version of their exhaust.

    Have you reached out to Novitec for any answers yet?
     
  18. harrish1985

    harrish1985 Formula Junior
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    #18 harrish1985, Jun 9, 2022
    The Novitec rep for North America didn’t seem to have many answers other than “their muffler doesn’t cause cat issues” when I told him I unplugged the tectronic while the car was completely off and then plugged it back in to make sure it was fully secure he basically told me that unplugging the tectronic even once will mess everything up etc. In any event I am away for a few days and the car codes were clear last night. I’ll keep an eye for sure but my primary concern is the cat converters running other than they need to.
     
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  19. harrish1985

    harrish1985 Formula Junior
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    #19 harrish1985, Jun 10, 2022
    FYI -- Novitec has 2 separate tectronics. The one on my invoice is F1 444 80. I'll discuss this with retailer on Monday.

    NOVITEC TECTRONIC
    Article No. F1 444 80 / 99
    To use with NOVITEC sport metal catalysts or NOVITEC cat replacement pipes to avoid error indications from the catalysts and GPF

    Together with a NOVITEC exhaust system
    Article no. F1 444 80

    Without NOVITEC catalysts or cat-replacement pipes
    Article no. F1 444 99
     

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