Is my car runnung Lean or Rich | FerrariChat
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Is my car runnung Lean or Rich

Discussion in '360/430' started by pmotoring, Dec 8, 2010.

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  1. pmotoring

    pmotoring Formula Junior

    May 8, 2009
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    PAT PAT
    #1 pmotoring, Dec 8, 2010
    Last edited by a moderator: Sep 7, 2017
    I have installed a set of FAB speed sport/race CAT, however I do get CEL, people been telling me that my F430 is running either too Rich or Lean finally I got a OBD2 read out. based on the reading can you tell me my car is runing fine or not

    Thanks
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  2. Ingpr

    Ingpr F1 Rookie

    Jun 30, 2009
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    #2 Ingpr, Dec 8, 2010
    The ideal air fuel ratio is 14.7:1 with a Lambda = 1
    I think that because your reading is less than one your system is running rich.
     
  3. m5guy

    m5guy Formula 3

    Aug 17, 2008
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    #3 m5guy, Dec 8, 2010
    What is the scale for that OBD II reading though? Is it actually Lambda or is it voltage, or something else? Second, how and when was that value acquired? Real time, or some stored value that is an average of some driving cycles? I'm asking the questions because I'm genuinely curious about how much useful info the OBD port monitoring can provide.
     
  4. SrfCity

    SrfCity F1 World Champ

    Nov 1, 2003
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    #4 SrfCity, Dec 8, 2010
    Yes, and your module is $11.
     
  5. SfefVan

    SfefVan Guest

    Nov 28, 2008
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    #5 SfefVan, Dec 8, 2010
    Last edited: Dec 8, 2010
    It looks like the 0.65 value is 650mV. Your A/F mixture would be running rich (lamba 1=450mV=stoichiometric point, above is richer, below is leaner). But you must dig deeper to find out if your engine is globaly running richer. Did you just start the engine? What was the engine temperature and air temperature? Whas the ECU in open or closed loop? With any kind of OBDII tool you can get a bit more usefull information. Keep in mind that in closed loop, the ECU keep cycling the oxygen sensors to produce a wave between the minimum and maximum value. A good running engine, fully warmed up, in closed loop and at idle should have waves oscillating between the min (100mV) and max (900mV) values.

    Lean : oscillation between <300mV and <500mV
    Rich : oscillation between >400mV and >600mV
    Bad oxygen sensor : oscillation limited between 400mV and 450mV

    Hope this helps ;)
     
  6. pmotoring

    pmotoring Formula Junior

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    #6 pmotoring, Dec 9, 2010
    Last edited: Dec 9, 2010

    The brand I am using is "LAUNCH"

    Thanks I think it helps, at least I understand my car is running rich.

    the reading is just based on engine starts for 60 seconds.

    the intake temp was 36C and the RPM was about 1,000

    Anything can change the setting of A/F mixture and resume to normal?

    I shall fully warm up the car and get another set of data, will post it later

    Thanks
     
  7. eric355

    eric355 Formula 3
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    Eric DECOUX
    #7 eric355, Dec 9, 2010
    Last edited: Dec 9, 2010
    The reading you took is on the POST cat O2 sensor (Bank1 sensor2). Difficult to say with such a data how you engine is running. 0.65V is on the rich side for a narrow band sensor, but after the cat it is less meaningful. Also, it is not clear if your engine was already in the closed loop mode or if it was still in the post start enrichment phase.

    Unfortunately, PRE cat sensors seem to be not available in the OBD2 data, AFAIK (at least it is the case for the F360), probably because they are wideband sensors.

    If you want a better diagnostic, let the engine warm-up and report the following data: fuel system status (closed loop or open loop), short term fuel trim (STFT) data, long term fuel trim (LTFT) data.
     

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