News

355 355 96 5.2 check eng light

Discussion in '348/355' started by Beetle, Dec 12, 2020.

  1. Beetle

    Beetle Formula Junior
    Silver Subscribed

    Apr 10, 2013
    776
    Hello All
    Check eng light.
    Codes P0133, P0139, P0153
    Could these codes be due to dirty injectors? I have rebuilt fuel mount a little while ago and the rubber mount was not good to say the least, wondering if I have rubber product in the injector top pre filters and car is maybe a little lean??. I had P0133 previously and replaced that post cat sensor. This time I drove it and these other codes came up as well. P1451 secondary air pump short to ground??? Air pump is working fine and the pump air intake filter is clean. Haven't had fault code recurrence for a long time. Any advice on where to look/fault find would be great
    TIA
     
  2. To remove this ad click here.

  3. Qavion

    Qavion F1 Veteran
    Silver Subscribed

    Feb 20, 2015
    5,121
    Sydney
    Full Name:
    Ian Riddell
    Isn't P0133 the right hand precat sensor?
    P0139 is the postcat (downstream)
    P0153 is the left hand precat (upstream)

    Just reading about P0139. This website seems to think that the engine is getting too much fuel during deceleration

    https://www.yourmechanic.com/article/p0139-obd-ii-trouble-code-o2-sensor-circuit-slow-response-bank-1-sensor-2

    Maybe the contaminants are stopping the injectors from closing? How often do you use an injector cleaner? Since the codes are for both sides, it could be due to contaminants.

    That webpage also mentions sticky throttles (although I can't see the connection).

    Does your scanner show long and short term fuel trims?

    Fuel mount?
     
    Beetle likes this.
  4. Beetle

    Beetle Formula Junior
    Silver Subscribed

    Apr 10, 2013
    776
    Fuel pump mount.
    Never used injector cleaner might try a bottle. When I did eng out service I replaced all pre/post cat sensors and temp probes. Car hasn't even done 500ks from service yet. I cut the old fuel filter apart after I rebuilt the pump mount. The filter was black. I'm wondering if some product has made it way to the injectors? I'm always abit cautious with these fuel injector cleaner/oil leak stop additives? Maybe I will try one
     
  5. Beetle

    Beetle Formula Junior
    Silver Subscribed

    Apr 10, 2013
    776
    I don't believe my scanner shows fuel trims
     
  6. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    10,631
    San Carlos, CA
    Full Name:
    Mitchell Le
    First, get a scanner that shows long term fuel trim and short term fuel trim. Those are big clues.
    Second, if your fuel filter was black, you might consider changing the deteriorating rubber bits inside the fuel tank at the pump.
     
  7. To remove this ad click here.

  8. johnk...

    johnk... F1 Veteran
    Owner

    Jun 11, 2004
    8,637
    New England/FL
    Aside from Mitch's suggestion, are you sure you have the rigth sensors in the right positions and/or connected tot he right plugs.
     
  9. Beetle

    Beetle Formula Junior
    Silver Subscribed

    Apr 10, 2013
    776
    Fuel pump rubber mount has been replaced. Any Brand scanners that you would suggest in regards to showing fuel trims?. All sensors and plugs are in the right spots and connected correctly.
     
  10. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    10,631
    San Carlos, CA
    Full Name:
    Mitchell Le
    I suggest Actron OBD2 scanner. Anything over $200 US will read fuel trims.
     
  11. Beetle

    Beetle Formula Junior
    Silver Subscribed

    Apr 10, 2013
    776
    Ok cheers. You don't happen to know parameters or where to get. I think I have to see certain readings on decel?
     
  12. To remove this ad click here.

  13. drbob101

    drbob101 F1 Rookie
    Owner

    Nov 26, 2012
    3,764
    Tinton Falls, NJ
    Full Name:
    Bob Ferraris
    Dash command is an app for your phone that uses a wifi OBD transmitter. It does ST and LT FT,

    The transmitter is $20 on amazon. Google if
     

    Attached Files:

    Qavion and Beetle like this.
  14. Beetle

    Beetle Formula Junior
    Silver Subscribed

    Apr 10, 2013
    776
    I'm leaning towards an injector fault BUT I'm certainly going to look at vacuum/exhaust leaks. Car starts, drives, idles and runs fine which is wierd. Might even check cat temps at warm up and running temps.
     
  15. Beetle

    Beetle Formula Junior
    Silver Subscribed

    Apr 10, 2013
    776
    Ok so my Actron scanner does read the STFT And LTFT
    Please see picture attached.
    From start up to running temp LTFRTM1% did not move. from 11.7%
    LTFRTM2% -4.9 and fluctuates.
    Everything else is working. When warm if you hold say 2500rpm for 20 then decel both STFT's straight to 0.0% so working?
    would LTFRTM1% 11.7 be upstream 02 sensor bank 1 fail?? Or is this an injector fault on this bank? I have bought a smoke machine to check leaks but LTFRTM1% 11.7 solid Is an issue. Any help would be great.
    TIA
    Image Unavailable, Please Login
     
  16. Beetle

    Beetle Formula Junior
    Silver Subscribed

    Apr 10, 2013
    776
    1 bottle injector cleaner 20 ltr fuel very spirited 50k drive No Check Eng light? LOOSE FUEL CAP when putting fuel in? Surely Not??
    Got home engine running check cat temps at back of cats where I could get to both within 5 degree C of each other (225/230C)
    Only change in LTFRM1% is solid 11.5 to now 12.5 solid. Everything else fluctuates. 0.0 on decel STFRM1&2%
    TIA looking forward to hearing your thoughts
     
  17. Qavion

    Qavion F1 Veteran
    Silver Subscribed

    Feb 20, 2015
    5,121
    Sydney
    Full Name:
    Ian Riddell
    The more I read about this stuff, the more confused I become.

    According to one website (non-Ferrari), the LTFTs are derived from post-cat sensors, so... you would perhaps suspect a faulty post-cat sensor. However, you've changed this already.

    On the same website:

    Resembles in what manner? Magnitude? Polarity?

    Also on that website:

    Swap or clean MAFs.

    Rich running conditions require less fuel (negative fuel trim). Lean running conditions require more fuel (positive fuel trim)

    Is your post cat right bank O2 sensor screwed in properly? Are you using extenders? Are they screwed in properly?
     
  18. Beetle

    Beetle Formula Junior
    Silver Subscribed

    Apr 10, 2013
    776
    Extenders yes.
    Done my head in to mate hahahaha and not to have a CEL has really got me stumped. See I understand the minor fluctuations BUT the solid LTFT has me beat. And I presume only one side. I'm going to smoke test the intake area and exhaust Friday. I'm presuming that 1 is bank 1 & 2 is bank 2. Bank 1 is RHD Bank 2 is LHD? That's correct I think. I will check extensions Friday as well. Right side post cat is the new sensor I replaced about 6 weeks ago.
     
  19. Qavion

    Qavion F1 Veteran
    Silver Subscribed

    Feb 20, 2015
    5,121
    Sydney
    Full Name:
    Ian Riddell
    Correct.

    I don't suppose it could be faulty from the factory?

    What's the reason you're using extenders?
     
  20. Beetle

    Beetle Formula Junior
    Silver Subscribed

    Apr 10, 2013
    776
    True I didn't think of that. I could put one of the original ones back in the check if any change. When I installed the rebuilt/new cores in Cats I was told I may get sensor sensitivity and that info was correct. They were done approx 2017 maybe before can't remember. They were definitely in there when I did 2017 eng out service. Hasn't done any work at all maybe that is an issue but I do start it and let it heat/fan cycle a few times regularly
     
  21. Beetle

    Beetle Formula Junior
    Silver Subscribed

    Apr 10, 2013
    776
    Extenders are on the post cats. I replaced Bank 1 upstream precat O2 sensor Not the post cat. I just looked at the post cat sensors i purchased when i did engine out service. They are not bosch i only used bosch in the upstream precat. The brand that is downstream post cat is called PEC. I tried some of these PEC ones in a HSV vehicle i have a couple of years ago and in 10 mins got a CEL saying !O2 slow to react! Now im wondering if this brand is not good at all. Think i might start with some gen bosch and see what the scanner says.
     
    Qavion likes this.
  22. johnk...

    johnk... F1 Veteran
    Owner

    Jun 11, 2004
    8,637
    New England/FL
    This might help in understanding fuel trim.
     

    Attached Files:

    Qavion likes this.
  23. Qavion

    Qavion F1 Veteran
    Silver Subscribed

    Feb 20, 2015
    5,121
    Sydney
    Full Name:
    Ian Riddell
    ... or confuse more :p

    This suggests all fuel trimming is done by the rear O2 sensors. So what do the front sensors do?

    LTFT is based on STFT exceedances, so you would expect the same sensors to be used for trimming.
     
    Beetle likes this.
  24. johnk...

    johnk... F1 Veteran
    Owner

    Jun 11, 2004
    8,637
    New England/FL
    No it doesn't. All trim is by the front sensor. The rear sensor only comes into play if it consistently sees a voltage significantly away from the 0.45 V level which indicates that the front sensor is aging and has a zero shift (shifting switch point). And that's only in cars set up to do so, of which the F355 is one.
     
  25. johnk...

    johnk... F1 Veteran
    Owner

    Jun 11, 2004
    8,637
    New England/FL
    #22 johnk..., Dec 14, 2020
    Last edited: Dec 14, 2020

    Expanding on the rear O2 sensor. It serves two purposes. 1) monitoring cat efficiency. To do that it looks at how fast the rear sensor signal changes. It is is following the front sensor it's an indication that the cats are bad. 2) Monitor the condition of the front sensor. If the rear sensor voltage is stable (relatively), then the level of that voltage (difference from 0.45V) tells the ECU about the switch point of the front sensor and the ECU attempts to correct for that.

    Understand this is a simplistic explanation.
     
    Beetle likes this.
  26. Qavion

    Qavion F1 Veteran
    Silver Subscribed

    Feb 20, 2015
    5,121
    Sydney
    Full Name:
    Ian Riddell
    We must be reading a different file, John

    Quote:

    "The rear oxygen sensor, located after the catalyst, is used for fuel trim corrections on some OBD2 vehicles. By virtue of its location, the rear sensor is generally protected from high temperatures and much of the contamination that affects front oxygen sensors. In addtion, the rear sensor sees exhaust gases that are equilibrated - they have been converted by the catalyst so that there is very little residual oxgen. This allows the rear sensor to respond to much smaller changes in exhaust gas oxygen content. In turn, it(sic) then possible for the rear sensor voltage to remain near the 0.45 volt switchpoint". This characteristic allows the rear sensor to be used for fuel control.... "

    I know it says "some", but this is the only time front and rear is used in the text.

    This disagrees with the Ferrari WSM and gives a valid reason for disagreement. Therefore... I am confused.
     
    Beetle likes this.
  27. johnk...

    johnk... F1 Veteran
    Owner

    Jun 11, 2004
    8,637
    New England/FL
    It's a matter of what is not said. The assumption is that the front sensor is working properly. Then the rear basically sits at 0.45V. If it's not, then it's because the front senor switch point has drifted for some reason like age or contamination. Thus based on the front signal the ECU would be biased toward rich or lean and looking at the rear voltage the ECU can see that and correct for it. But understand, this is a great oversimplification and basically relates to the engine running a a steady state condition: throttle position, RPM, etc. Sudden changes in throttle position, on or off, will cause the rear sensor voltage to shift significantly. Obviously, the logic in the ECU is designed to recognize this.


    The WSM basically says the same thing straight out.

    Image Unavailable, Please Login

    Note that in both cases it's talking about a correction to what the front is telling the ECU.

    The whole idea of using the rear to further correct trim is just for pollution. Cars run fine on just the front. But as noted, if the front starts to age the ECU will be biased towards rich of lean and the Cats won't work as good. Ultimately, the front sensor fails and the trims max out and the CEL comes on. But until it does the car is dumping more garbage than designed for into the air. When the rear sensor is incorporated it's basically saying, " Hey, wait a minute. The front sensor is telling the ECU it's running correctly but based on what's coming put of the cats it's a little off. I can fix that. " And it keeps the car running cleaner even though the front sensor is on the way out.
     
    Beetle likes this.
  28. Qavion

    Qavion F1 Veteran
    Silver Subscribed

    Feb 20, 2015
    5,121
    Sydney
    Full Name:
    Ian Riddell
    This makes sense, thanks John.... as does the WSM.

    The file introduces random abbreviations and values without explanation. LEV? FTP? DTC? Switchpoint? 0.45 volts? It assumes you know what these are. It's only when you read other documents that you start to understand what is going on.

    What is zero shift? (no sensor voltage change over a range of engine speeds/conditions?)

    What do you mean by "shifting switch point"? What is shifting? What is being switched?
     
    Beetle likes this.

Share This Page