430 - Do rear/post 02 sensors measure temperature at all - I know on the scud I believe they do | FerrariChat

430 Do rear/post 02 sensors measure temperature at all - I know on the scud I believe they do

Discussion in '360/430' started by carguy007, May 10, 2021.

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

  1. carguy007

    carguy007 Formula Junior

    Apr 24, 2013
    839
    Gents,

    was curious if post 02 sensor measuer temp at all on a 430 or if this is solely done by the thermocouplers. Scud has not thermocouplers and post 02 apparently measure temp too.

    On start up when the car is dead cold I get codes on both banks for cat over overheat, protection enabled. This is a virtually impossible scenario as the cars dead cold and happens with in 30 seconds of start up. Was just going to order the two sensors and replace as they are $50, but wanted to hear some thoughts experiences.

    What are the odds that both thermocouplers are bad, seems strange. I am running headers with stock secondary cats. I was thinking that the 02 wires were twisted quite a bit to get the extenders in place and this may be the cause.

    Any imput greatly appeaciated.
     
  2. EastMemphis

    EastMemphis Formula 3
    Owner Silver Subscribed

    May 25, 2019
    1,719
    Memphis, TN
    Full Name:
    John
    From my investigations of the O2 (aka Lambda) sensor, I can see only one function for the unit. The sensor generates a very low current which measures the oxygen in the exhaust gases compared to the ambient. There's actually a heater in the O2 sensor that warms it up so it's pretty much impossible for the standard O2 sensors in these cars to detect and measure temperature.

    A possible problem that can arise from twisting the connection is that the ambient airflow, which flows through the insulation around the wires, may be cut off. If that happens, then the sensor will malfunction. If the wires were damaged, that can also lead to false indications.

    Odds are that the insulation was twisted with the wire and now there's no flow of air happening with the sensor. It's kind of odd that they use the insulation for the wire for ventilation but there it is. If you look closely at the insulation layer, you'll notice it's not tight on the wire. That's for the airflow.

    I would suggest that for folks replacing their headers, or adding extenders/mini-cats, they take the trouble to disconnect the O2 sensor from the connector before trying to unscrew the sensor. I believe in the 430, that requires removing the airbox.
     
  3. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,829
    Isle of man- uk
    Around 2007 on the ordinary 430 they stopped fitting separate thermocouples to the cats. They still have the connections but are blanked off.
     
  4. carguy007

    carguy007 Formula Junior

    Apr 24, 2013
    839
    Yes - I agree and am aware of everything above. 430 does require removing airbox. I am more curious if post 02 could cause that cat over heat code I get on startup or if it has to be the thermocouplers. The car run's great and no issues there and the cats are not overheating. I can not see how a faulty or damaged post cat 02 could create this issue and was leaning towards the thermocouplers, but is odd that both went and that the car runs great.
     
  5. carguy007

    carguy007 Formula Junior

    Apr 24, 2013
    839
    I have a 2007 but it definitely has thermocouplers it bolts in right next to the O2. The only cars I have seen without are the Scuds but could be wrong.
     
  6. brogenville

    brogenville Formula 3
    Rossa Subscribed

    Apr 24, 2012
    2,005
    UK
    Full Name:
    Robin
    Later cars without thermocouples use an algorithm to calculate exhaust temperature.

    This is what I’m told at least!


    Sent from my iPhone using FerrariChat
     
    Qavion and 360trev like this.
  7. 360trev

    360trev F1 Rookie
    Project Master

    Oct 29, 2005
    4,241
    Gibraltar
    Full Name:
    360trev
    Correct!

    I cite references for all those who don't believe me...
    https://link.springer.com/chapter/10.1007/978-3-658-16988-6_79

    Its called 'Exhaust Gas Temperature Modelling' and its been built into Bosch Engine Management since it became drive by wire using a Digital Throttle Pedal, so in our case since introduction of the Ferrari 360's. Why didn't they use the EGT Modelling instead of using temperature probes and a Cat ECU? Well that's a discussion for another time..

    @carguy007

    Q. Can you actually post the exact fault codes given?
    Was it (LHS) P1454 or (RHS) P1446 for Catalyst Protection Active?

    ------

    Lets give a brief summary of the O2 Sensors used on 360's, F430 and the 430 Scuderia's for a good understanding of this topic for those interested in how it works.

    Q. How many O2's are fitted and where are they located?
    On the 8 cylinder engines there are two oxygen sensors per bank of cylinders. So 4 oxygen sensors in total for the entire engine.
    • Primary O2 sensors are installed in the headers/manifolds before the cats.
    • Then the main cats are fitted (which use a chemical process to clean up the emissions in the tailpipe).
    • Finally the Secondary O2 sensors are installed (post or after) the cats. This is repeated on both Left and Right hand side banks.
    So it looks like this;

    1. Engine Block exhaust emissions
    2. 4-Cylinder Header/Manifold (Header Cats) per bank
    3. Primary Wideband O2 Sensor (6-Pin LSU 4.2 [Pre-Cat]
    4. Main Catalytic Converter
    5. Secondary Narrowband O2 Sensor (4-Pin LSF) [Post-Cat]
    6. Exhaust Control Solenoid Valve
    7. Exit out of the vehicle tailpipes..


    Q. What are the Primary O2's used for?

    In a nutshell all they do is tell us how much oxygen content in in the tailpipe. Turns out this is a really important part of the puzzle!

    Why, lets explore further.. Well after the engine is first started, and is idling, the Bosch Motronic software goes into ‘Open Loop’ operation during the warm-up cycle, completely ignoring the Primary wide-band Oxygen sensors which are not yet ready to use, they are too cold so don't yet give accurate readings. In this generation of sensor it takes approximately 30 seconds to heat up. The sensors have a built in 'heating element' which needs to be powered and under control of another Bosch IC chip built directly into the (Engine Control Module) ECM, the Bosch CJ125 O2 Controller which is a control and amplifier circuit chip. It can also detect faults with the O2's heating element itself or the power amplifier used to power the O2 sensor so it provides accurate readings. When operationally ready these wideband O2 sensors output a voltage signal between 0V to 5V to indicate the varying range of (Air Fuel Ratio) AFR at any given state to indicate the current fuel ratio emitted by the burning the mixture of petroleum and air. This is important as it helps keep fueling exactly where we want it.

    The O2 sensors are sampled by the engine software every 10ms (milliseconds) or 100 times per seconds and the value itself is converted from a voltage into a numeric value (Analogue to Digital conversion) in 16-bits which can be used by the algorithms to decide to adapt the fuel mixture to match the target air to fuel ratio under the given engine load, rpm and conditions. This is called fuel adaption and it happens continuously to trim the fueling by either running richer or leaner to reach the desired target fuel ratio dictated by the maps.

    During ‘Open Loop’, the engine management software completely ignores the signal from the Primary Oxygen (O2) sensor and calculates the air/fuel ratio based on inputs from the Coolant temperature sensor and Air Flow Meter sensors, but mainly from pre-programmed calibrations instead. The software will stay in ‘Open Loop’ while the O2 sensor isn't fully up to temperature and the temperature is below a specified threshold.

    When conditions are reached and the O2 is ready, the system goes into ‘Closed Loop’ operation. When in ‘Closed Loop’, the software will begin to calculate accurate air/fuel ratio (for injector on-time) based on the primary O2 sensor and Air Flow Meter reading, among other readings like battery voltage compensation and so forth. This allows the air/fuel ratio to stay very close to what the factory programmed calibration maps dictate.

    As the o2 sensors get older they 'age', that is they get slower to respond and thus your mixtures are kept under less 'control'. They can also get contaminated and this can generate quite a number of different CEL (Check Engine lights). In fact you'd be surprised just how many different CEL's this can produce...

    Q. What are the Secondary O2's used for?

    In a nutshell, Emissions 'Verification'. The secondary O2's in this use-case is used for emissions verification. Put simply the primary o2's (the accurate wideband ones) measure the exact AFR and the secondary O2's then simply check how efficient that process was at reducing the amount of O2 after they have been through that process. If emissions wasn't a concern you wouldn't in fact even require secondary O2 sensors at all. Ironically the consume energy at all times that the engine is running (upto 10W per sensor) and only become 'useful' when the cats are no longer working efficiently to 'tell' the owner of the car through a CEL that the cat efficiency is no longer up to standard. Think of the millions of 10W sensors on all the time and imagine how much fuel that's consuming, just to monitor the use case that the cats are no longer working well which probably in the case of Ferrari's is every 20 years due to typical mileages the vehicles do... Oh well...
     
  8. carguy007

    carguy007 Formula Junior

    Apr 24, 2013
    839
    Yes it is the same codes you mentioned on both banks. Car is running headers which deleted the cats. Also running the extenders (no 90 degree bend) that have proven to be useless. Should I opt for the ones with 90 degree bend.

    Prior to header install of headers and exhaust (S-Line) had no codes. LH and RHboth show the same codes. I find it odd these are triggered 30 sec of starting car with the exception of the car cat effeciency threshold code. I thought I was careful with the Thermocouplers and what are the odds I broke both them. Given your explanation I don't see how the post 02 could trigger these codes as it is nothing to do with themp.

    @360trev

    p0438 Left hand temp sensor high inpug,
    p1454 - Protection Activation for LH Cat,
    p0340 - Cat below effeciency Threshold

    Great read on EGT modeling had no idea about that.
     
  9. 360trev

    360trev F1 Rookie
    Project Master

    Oct 29, 2005
    4,241
    Gibraltar
    Full Name:
    360trev
    So just to answer precisely the questions.

    Firstly, you don't actually need secondary o2's but the primary ones are very important and I consider them a service item. Change the primary ones but don't spend a penny on secondary ones if you don't have to. *In places which allow such changes personally would just deactivate cat efficiency monitoring in the engine software... IHMO cat efficiency monitoring and secondary o2s are a waste of space on low mileage cars.
    Q. Can you double check your first fault code, was it actually P0348 and P0340 ?

    If so I know what's wrong...
     
  10. carguy007

    carguy007 Formula Junior

    Apr 24, 2013
    839

    @360trev

    I think the code in reference is the P0438 which is correct and states" Left Hand Catalytic Converter Temperature Sensor (High Input)
    Hopefully that is helpful and arms you with what you need to confirm your suspicions.

    For reference my car is a 430 built in 2007 with thermocouplers. These are the codes on both banks. I am pulling these using Launch x431.

    LH:
    P0438, P1454, P0430

    RH:
    P0428, P1446, P0420

    I agree that post 02 are useless and wish I did not have them. CA is super strict with their emmission testing unfortunately.
     
  11. carguy007

    carguy007 Formula Junior

    Apr 24, 2013
    839

    I think the codes you referenced would camshaft position sensor related. Am very intrigued how this may all be tied together. What were your inital thoughts?
     
  12. 360trev

    360trev F1 Rookie
    Project Master

    Oct 29, 2005
    4,241
    Gibraltar
    Full Name:
    360trev
    Sorry I mis-read what you wrote in the thread. For some reason I thought your car was a 430 Scuderia and ofcourse P0438 doesn't exist on a 430 Scuderia (I double checked ALL the Scud firmware's) but it P0348 does. So I assumed (if your car was a Scuderia) that you'd perhaps mistyped it, Nothing else.

    Ok, so I just cross referenced an earlier F430 firmware from a 2006 MY and dumped the Fault code table using my own proprietary tools. These are significantly more reliable that 99% of OBD tools as I actually find the fault codes from intelligently analyzing the firmware itself!

    Here's the results;

    LH: P0438 P0437 ..... P0436 Catalyst Temperature
    RH: P0428 P0427 ..... P0426 Catalyst Temperature
    --
    LH: P1454 ..... ..... ..... Catalyst Protection Active
    RH: P1446 ..... ..... ..... Catalyst Protection Active
    --
    LH: ..... P0430 ..... ..... Catalyst Efficiency
    RH: ..... P0420 ..... ..... Catalyst Efficiency

    --

    So all of your faults are entirely related to Cat Temperature, Cat Protection and Efficiency of Cats.

    If you want ALL this resolved 100% guaranteed and quickly, for it to never throw these faults related to this ever again I would just go with software deletion. No need to thow more parts like secondary o2's, thermistor probes, etc. and face re-occurring nightmare of future hassle (which will always come back when trying to cheat the efficiency monitoring), just pm me and I can help you fix in software. Job done.
     
  13. Qavion

    Qavion F1 World Champ
    Silver Subscribed

    Feb 20, 2015
    11,484
    Sydney
    Full Name:
    Ian Riddell
    Trev, would you have the ECU pin numbers that the O2 sensors are hooked up to? I'm trying to resolve a conflict in the Scud wiring diagrams. There's a table in the wiring diagrams which shows all the functions of the ECU pins, but it doesn't match the diagrams. Here is an example (left hand side):

    Image Unavailable, Please Login

    According to the diagram above, the left hand O2 sensors are feeding pins 5, 71, 52, 70, 51, 63, 68, 69 on the LH ECU. The pin table says that most of these pins are for the rhs lambda sensors:

    Image Unavailable, Please Login

    Also wondering why there are 6 pins on the front sensors.

    Thanks for any insight (sorry for the thread hijack).
     
  14. carguy007

    carguy007 Formula Junior

    Apr 24, 2013
    839

    @360trev
    Took your advice and PMed
     
  15. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,829
    Isle of man- uk
    Mine is an 08 and the connections are blanked off, they stopped fitting during 07 according to my ferrari workshop.
     
  16. 360trev

    360trev F1 Rookie
    Project Master

    Oct 29, 2005
    4,241
    Gibraltar
    Full Name:
    360trev
    I'll dig out the wiring but currently not at home.

    I answered the question to 6 pin and 4 pin in my response but not explicitly. They are different sensors.

    Primary o2 is a Bosch LSU 4.2 Wideband sensor which gives an accurate AFR reading across a wide spectrum of ratios. The secondary o2 is a cheaper Bosch LSF 4 sensor which isn't as good but good enough for emissions purposes. S


    Sent from my VOG-L29 using Tapatalk
     
  17. Qavion

    Qavion F1 World Champ
    Silver Subscribed

    Feb 20, 2015
    11,484
    Sydney
    Full Name:
    Ian Riddell
    Ah, thanks. There was so much good information here, I think I was overloaded :D
     

Share This Page