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348 O2 sensor question

Discussion in 'Technical Q&A' started by spang308, Oct 3, 2005.

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  1. spang308

    spang308 Formula Junior

    Jul 17, 2004
    893
    York, PA
    #1 spang308, Oct 3, 2005
    My friend has a 1992 348 and the check engine light came on breifly. He called me in a panic and I went over to take a look. I pulled 1211 codes out of both ECUs and also a 1212 out of the right ECU. I unplugged both the O2 sensors and tested them with the engine idling. The left one was reading a little off, but the right one was DOA. Wouldn't even register on the voltmeter. I looked though his service history and the car had 2 OEM O2 sensors installed 3 years ago. Do 348s crap out O2 sensors this fast?

    Also, I looked on Bosch's website and they list #13120 as the sensor for this car, however the right and left sensors have different plugs. Is there another part # for right and left or do you have to modify the wiring. It's a two wire sensor, but I'd rather a plug and play instead of mucking with the connectors. I also plan on testing his MAS to make sure they are balanced and set correctly.

    Thanks in advance for any help.

    John
     
  2. ronr

    ronr Formula Junior

    Oct 30, 2002
    813
    DFW, TX
    Full Name:
    Ron
    #2 ronr, Oct 3, 2005
    Good question. I got a 1212 code, and also a 1114, which I think is O2 sensor related. Here are all the Lambda codes I've seen. What's the difference between these?

    Lambda sensor 1114
    Lambda regulation Additive value for self adaption 1211 (O2 sensor)
    Lambda regulation multiplicative value for self adaption 1212
    Lambda regulation intake manifold compensation 1212
     
  3. spang308

    spang308 Formula Junior

    Jul 17, 2004
    893
    York, PA
    #3 spang308, Oct 4, 2005
    Any ideas?
    Is the think tank dry?
    Why do Zebras have stripes?

    John
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,932
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #4 Steve Magnusson, Oct 4, 2005
    John -- More of a question than advice, but it might be more interesting to measure the O2 sensor output while it's still plugged in and running closed-loop. When you unplug the O2 sensor at warm idle, it will just default to whereever the manual tweak is set -- i.e., if it's set lean, it would just read a constant near 0V (or to the rich side, a constant +1V). Might give you a better comparison to see if one side is varying properly in the closed-loop mode, and the "dead" side is truly dead -- just a suggestion...

    It's also been reported here that adding a better "ground" to the body of the O2 sensor can be helpful (but I don't understand why since the O2 sensor should be well-grounded by the ground connection for the internal heater)
     
  5. ferrarilou

    ferrarilou Formula Junior

    Apr 13, 2004
    513
    US
    Full Name:
    Lou Menditto
    #5 ferrarilou, Oct 4, 2005
    Are you sure you're looking at the right wires for the 348 O2 sensors?
    You may very well be right, but the parts book shows only one
    part number for both sensors, so the book claims they are the same.
    Also, the O2 sensors I've seen for that engine have been 4-wire,
    splitting off into two pigtails at the connector end. One of the
    pair of wires uses a male plug, the other uses a female plug. So,
    for the two O2 sensors you wind up having 4 plugs ... all arranged
    in a row in the tight area under the oil filter. Most of my experience
    is with the Mondial-T however, which also lists the same O2 sensor
    for part of the series.
     
  6. BT

    BT F1 World Champ
    Lifetime Rossa

    Mar 21, 2005
    15,291
    FL / GA
    Full Name:
    Bill Tracy
    #6 BT, Oct 5, 2005
    The Ferrari 348 repair tips page lists both a universal and an oem fit o2 replacement for the 348. The universal is around $60 but you have to splice the factory pigtail in, and the factory fir replacement is around $180. Both sides of the engine use the same part number.
    BT
     
  7. Ksullender

    Ksullender Formula Junior

    Sep 3, 2003
    887
    USA
    #7 Ksullender, Oct 7, 2005
    You can further troubleshoot by switching the left and right O2 sensors and see if the code moves sides, this may help isolate the problem.
     

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