Need help with 458 o2 sensor CEL and aftermarket exhaust | FerrariChat

Need help with 458 o2 sensor CEL and aftermarket exhaust

Discussion in '458 Italia/488/F8' started by Pazzo009, Jan 17, 2019.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. Pazzo009

    Pazzo009 Formula Junior
    Silver Subscribed

    Mar 30, 2014
    358
    Northern Atlanta Area
    Full Name:
    Marc C
    I have been having an ongoing issue with the 458 and a check engine light. Here is the scenario.
    My 458 has Fabspeed headers, sport cats, and a S-line cat back exhaust that I installed later on.

    When I took delivery in January of 2018 I wasn’t really driving the car because it was winter. I installed my exhaust around April. As time went on, I started getting: "Catalyst temp not plausible", see dealer on the LFT. The code on the scanner says- P2097 Post catalyst fuel trim system too rich bank 1.

    I bought a scan tool luckily and was able to clear the codes. However, it should be known that after this light has appeared, if I continue to drive 10-30 miles, an Check engine light will stay on, and the car will go into limp mode until I clear it. This issue over time has increased in frequency. It has come on as much as 3 times in a 40-50 mile drive. Note* I have put about 2800 miles in the car since purchase. Current miles is about 9300

    My technician and I assumed over this time that the aftermarket sport cats were affecting the o2 sensors. I installed o2 extenders hoping this would correct the issue. It did not. So then we said, perhaps the o2 sensor is actually bad. I installed a OEM one yesterday on bank 1 (pass side) and it made no difference.

    This issue is now becoming a significant burden to my enjoyment of the car. More importantly, I keep having to clear the code thus the ECU is not “ready” so I can’t get the car inspected. It appears my only options at this time is to either tune the car, which I’m reluctant to do and it’s a significant cost. Or return it to stock exhaust setup.

    To my automotive knowledge, while the timing of installing a cat back exhaust is coincidence that this issue became present, the cat back is exhaust is AFTER the o2 sensors so I cannot understand how that would affect it.

    Any advice or insight? Has anyone dealt with this after installing exhaust components?

    Thank you
     
  2. PJxxx

    PJxxx Karting

    Sep 14, 2017
    129
    Full Name:
    PJ Cusano
    Out of curiosity, battery is tip top after storage period?
     
  3. tomhargr35

    tomhargr35 Rookie

    Sep 25, 2012
    2
    Have to tried an O2 sensor eliminator? Magnum tuning sells them. I was thinking about trying them on my 355
     
  4. JohnTz

    JohnTz Karting

    Jun 21, 2018
    212
    Inverness, IL
    Full Name:
    John Tz
    It’s the sport cats. Put the original cats back on and all will be good. That is always the risk with sport cats. Most people require a tune for the CEL to be eliminated when the stock cats are exchanged.
     
  5. obbob

    obbob Formula Junior
    Silver Subscribed

    Aug 14, 2017
    774
    I'm no expert, but if the error your getting is related to fuel mixture, I dont' think that's the cats. High flow cats risk causing a P0420 code, which is cat not running efficiently.

    A common cause of a P0420 is an exhaust leak. Since it did not seem to happen until you installed the catback, my guess is your catback was not installed properly.

    It could also be your headers or cats developed a leak later on. I would check everything if you can, but start with the catback.
     
  6. Pazzo009

    Pazzo009 Formula Junior
    Silver Subscribed

    Mar 30, 2014
    358
    Northern Atlanta Area
    Full Name:
    Marc C
    I will take that into consideration, but I do not have a P0420 code. Plus every time it's the same bank and same code. I just can't see how straight piping AFTER the sensor would affect this...Unless, could a change in back pressure affect the sensor?

    Thats what I was thinking. What is irritating is that I bought the car CPO and I was not told it had the headers and sports cats. I only found out while installing the cat back system. While it was a $9000 gift, it's not what I would have wanted to do to the car for the very reason of when you start messing with headers and cats, you need a tune or other bugs can come out.

    Yes, I keep it on a tender.
     
  7. obbob

    obbob Formula Junior
    Silver Subscribed

    Aug 14, 2017
    774
    Sorry I meant to write P2097. P0420 is the code most commonly caused by high flow cats or no cats. Yours (P2097) might be cats, but can also be an exhaust leak
     
  8. FerrariCognoscenti

    FerrariCognoscenti Formula 3

    Jan 19, 2021
    2,429
    East Coast
    What was the resolution to this issue?


    Sent from my iPhone using Tapatalk
     
  9. agturbo

    agturbo Rookie

    Jul 10, 2020
    7
  10. Shorn355

    Shorn355 F1 Veteran
    Rossa Subscribed

    Jan 13, 2011
    6,859
    Colorado
    Full Name:
    Scott
    FWIW you might check/have checked the secondary air valves - I realize you have a lot of aftermarket equipment and the various responses are probably much more informative and appropriate than mine but my CEL was on in my 2014 458 Spider (all stock however) yet the car was running/starting fine - turned out to be the secondary air valves - apparently they can get carboned up and trigger the CEL - Just something to consider - Cheers :)
     
  11. fazooley

    fazooley Formula Junior

    Apr 15, 2005
    387
    For cat delete's on the 458 the following codes are blocked for 2 bank engines.

    P0420/P0421 Cat Converter System, bank 1- efficiency below threshold
    P0170 Fuel Trim Malfunction (Bank 1)
    P0171 System Too lean (Bank 1)
    P0172 System Too rich (Bank 1)
    P0430/P0431 Cat Converter System, bank 2- efficiency below threshold
    P0173 Fuel Trim Malfunction (Bank 2)
    P0174 System Too lean (Bank 2)
    P0175 System Too rich (Bank 2)

    Depending on who is doing the tune with some you'll leave the sensors connected, and some will ask you to unplug.
     
  12. MicroFirm

    MicroFirm Karting

    Dec 6, 2010
    231
    Colorado
    Full Name:
    Frank
    Save your time and money and do try them, you will wind up throwing them away and it's money down the drain since they will not give you any money back.
     

Share This Page