AFR Readings

Thread in 'Technical Questions' started by mallyauto86, Oct 5, 2016.

  1. mallyauto86

    mallyauto86 Member

    Joined:
    Jan 9, 2011
    Posts:
    38
    Likes Received:
    0
    hi everyone, i have a rather large dilema,

    recently i have baught a Blitz turbo altezza through a well known UK based import company,
    now i thaught it would be a good idea after a 2000km trip to check on the old AFRs.
    so i have added a wideband sensor next to the original O2 sensor wich is just after the down pipe and wastegate.

    now i used the bung supplied in the innovate kit the sensor does not pertrude and the hole i have drilled is probs 1 mm all the way round smaller and the sensor does not pertrude into the exhaust.

    i have crazy AFR's, 18. 22 ish cruising and 14 to 15 on full WOT, this litrally scares the shit out of me to be honest but could it be due to the positioning of the sensor ? i know the values wont be 100% as i have a verry tiny exhaust leak but being that far out is ofcorse just off putting. car is run only on Vpower and has a blitz ACCESS ECU mapped for the turbo setup in japan on there normal pump fuel according to the importer, now having only had this AFR on it since today i have done over 3000km since i have baught the car, surely with an AFR like that it would have destroyed the engine, the spark plugs also look quite "normal" the bottom has a nice black colour, although there is not really any soot on the bottom when you wipe them with your finger.

    so i am hoping some people can tell me if i should be actually runing the thing as it is....
     
  2. yogi bear

    yogi bear Active Member

    Joined:
    Jan 22, 2009
    Posts:
    3,126
    Likes Received:
    0
    Location:
    soufend innit
    If those readings were correct. The engine would have melted already. And it wouldn't even run at 22:1
     
  3. mallyauto86

    mallyauto86 Member

    Joined:
    Jan 9, 2011
    Posts:
    38
    Likes Received:
    0
    After recalibrating the afr sensor i am getting 12 at wot but only after 5000rpms lower than that is still verry high around 16 to 22 varies allot depending on throttle position. I have now confirmed i have a manifold leak. Would this cause the issue ? Car does have a lumpy spot around 2500 3000 rpm ....
     
  4. r3k1355

    r3k1355 Well-Known Member

    Joined:
    Nov 8, 2007
    Posts:
    3,369
    Likes Received:
    129
    Yea sounds like you've got a few issues you need to sort before worrying about the readings.

    sort all the exhaust leaks out, make sure you've got a really good earth for the sensor as they can be sensitive, re-calibrate it again and take more readings.
     
  5. mallyauto86

    mallyauto86 Member

    Joined:
    Jan 9, 2011
    Posts:
    38
    Likes Received:
    0
    i am looking into changing a few sensors on the engine too to be honest, air flow meter for starts...
     
  6. 2JvLo

    2JvLo Member

    Joined:
    Sep 29, 2016
    Posts:
    61
    Likes Received:
    3
    Location:
    Netherlands
    A leaking exhaust would explain your readings. But if your wideband reads it's way to lean, so wil the original sensor! you'd better first fix the exhaust and not or later replace those sensors.

    "if it ain't broken, don't fix it"
     
  7. r3k1355

    r3k1355 Well-Known Member

    Joined:
    Nov 8, 2007
    Posts:
    3,369
    Likes Received:
    129
    and if you are set on replacing sensors then it go's without saying do not use cheap crap off eBay, otherwise you'll end up fixing one issue and creating two more.
     
  8. mallyauto86

    mallyauto86 Member

    Joined:
    Jan 9, 2011
    Posts:
    38
    Likes Received:
    0
    will be ordering sensors from toyota dealer, but yes i am looking into fixing exhaust, replaced with new plugs today did a few pulls still showing rather lean but plugs are ok ish porcelaine is a tad whiteer than id like. anyway fix exhaust report back, may order a power fc anyway to get more powerz lol
     
  9. Vlad_SX

    Vlad_SX Member

    Joined:
    Mar 5, 2012
    Posts:
    134
    Likes Received:
    0
    Location:
    Brasov/Bucharest, RO
    The Bosch LS sensors need to reach the exhaust flow, if they don't, they read exactly as your's reads. At 16+AFR @ WOT, your engine would run very poorly, have knocks and missfires. If it runs well, it's the sensor position. Recalibrate it to after. Cheers
     
  10. mallyauto86

    mallyauto86 Member

    Joined:
    Jan 9, 2011
    Posts:
    38
    Likes Received:
    0
    ok will move the sensor to the down pipe and check after.
     

Share This Page