catalytic converter temperature not plausible | FerrariChat

catalytic converter temperature not plausible

Discussion in 'California/Portofino/Roma' started by Cockney.mike, Aug 18, 2015.

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  1. Cockney.mike

    Cockney.mike Rookie

    Dec 2, 2012
    24
    Silicon Valley California
    Full Name:
    Mike
    I thought I would post my experience with an error message I got on my 2013 California as I could find no information on the internet trying to research this issue.

    I had a problem with the “catalytic converter temperature not plausible” error message occurring when my "California" was started after about 3 hours of it being parked after a drive. Before this message displayed, the engine stumbled and miss-fired for several seconds. Additionally, when starting the car after overnight parking, it sometimes sounded really rough for a while. Both of these problems were highly intermittent only occurring perhaps every 15 to 20 days. On the road, once warmed up, the car ran perfectly.

    The car was in the dealer multiple times for this problem, being off the road for almost 7 weeks in total. Finally the dealer discovered two of the valves on the fuel rails (one each side) were not shutting off completely and fuel was leaking very (very) slowly into the two cylinders. Presumably this made the mixture too rich when the car started, triggering this error message.

    Two new fuel rails fixed the problem completely.
     
  2. Peter P

    Peter P Karting

    Dec 22, 2011
    129
    Boston area
    Mike, thanks so much for this post. I too have had this issue intermittently over the past several years on my 2013 California 30. The dealer has not been able to replicate or diagnose. I'm sending them a copy of your post.
     
  3. keithos27

    keithos27 Formula 3

    Oct 26, 2012
    1,225
    Full Name:
    Keith
    For what it's worth, I've seen similar error messages on my Cali T when the battery wasn't sending proper voltage to the computer. Just a tidbit to take with you and have your dealer check your battery...
     
  4. Cockney.mike

    Cockney.mike Rookie

    Dec 2, 2012
    24
    Silicon Valley California
    Full Name:
    Mike
    Let me add a little more to this story.
    The dealer could never reproduce the problem.
    First time in the dealers they reset everything and went through the whole engine “learning” process. On the next visit, they sent both ECU’s back to FNA, reflashed them and installed new software in the car. On the final visit, I actually spoke to the senior technician and explained the problem in detail, when it happened and the symptoms. He immediately suspected the fuel rails as he had another car in the shop with a somewhat similar problem and he showed me the leaking fuel rails that had just been replaced on that California model (I can’t remember what year it was).
    Before the fix, sometimes when starting the car, I heard a loud whirring noise around where the fuel pump was (from inside the car, towards the back, on the passenger side)…this noise has stopped since the fix.
     
  5. 4th_gear

    4th_gear F1 Rookie

    Jan 18, 2013
    4,425
    Full Name:
    Michael
    #5 4th_gear, Aug 20, 2015
    Last edited: Aug 20, 2015
    The sensors in your car are probably correct.

    There's a serious problem that can arise from fuel leaking into the cylinders. The fuel mixture would be too rich and this can foul the spark plug(s). If that happens, the plug(s) can misfire, unburnt fuel will then get into the exhaust and poison the catalytic converter on that side of the dual exhaust. The extra vented fuel will in turn cause the cats to run too hot and melt the catalyst material. Here's what can ensue *if* the cats are damaged:
    ...bits and pieces of melted catalyst will usually come apart inside the honeycomb mesh that the cat is formed as and this will occasionally block the passage of exhaust gases, causing further problems which will include a rough engine, loss of power, eventually rattling noises from the proximity of the cat(s) and very dramatic driveability issues. The whole car can buck as chunks of loose, destroyed catalytic material momentarily block passage of exhaust gases, like someone suddenly inserting a proverbial "banana(s) up the tailpipe".

    If you then park the car and let it cool off, the engine may run OK under low throttle because the bits and pieces settle back in place and shrink as they cool. You can limp home with low throttle as high throttle will push enough exhaust through the mess to displace the debris, enough to block the exhausts again. It all depends on how the broken off pieces of catalyst sit inside the cat, sometimes they will settle back and open up the passage for exhaust, sometimes the opposite happens.​

    The problem tends to "fuel itself" in a vicious cycle. It is not difficult to diagnose but replacement of the cats is expensive. Since the car should still be under warranty, a straight replacement is in order.

    Obviously, the issue of the fuel rail leaking gasoline into the chambers need to be fully resolved before the car is used again.

    Good luck and keep use abreast!
     
  6. Angioman

    Angioman Rookie

    Aug 20, 2014
    2
    I have been getting the same message. It happens even after the car has been parked overnight. A friend suggested it was a batch of poor quality gas and suggested a fuel treatment. The message went away after I tried the treatment but then returned. I tried the treatment again and it went away but then returned again. Is the going away of the message coincidental? Unfortunately my vehicle is a 2013 and out of warranty.
     

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