348 - Check Engine light - ECU code 4121 | Page 2 | FerrariChat
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348 - Check Engine light - ECU code 4121

Discussion in 'Technical Q&A' started by goyal99, Jun 22, 2004.

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  1. airbarton

    airbarton Formula 3

    Nov 11, 2002
    1,462
    Kennesaw, Ga.
    Full Name:
    Chuck Barton
    #26 airbarton, Jun 24, 2004
    Here is a related issue. I managed to find a considerably cheaper alternative to the OE O2 sensor. Bosch makes a universal sensor, Part # 15727 that works perfect on the 348. I know because I have replaced both of the sensors in my car with them. Believe me when I tell you they are much less expensive than the dealer. The dealer charges $265 a piece for OE replacements but you can get the universals for about $60 a piece. The other nice thing about them is they are a stock item @ Napa, Auotzone, or Advance auto parts. All you need to do is keep the connectors from the old sensors. I had a similar problem as this thread desribes and solved it by replacing the sensor. Here is a link for more info.

    http://www.boschusa.com/AutoParts/OxygenSensors/HeatedSensors/
     
  2. goyal99

    goyal99 Karting

    Mar 5, 2002
    185
    Upstate NY - USA
    Full Name:
    V K
    #27 goyal99, Jun 24, 2004
    Charles - thanks for the info on BOSCH Universal O2 sensor...Yes, I checked my local Autozone and they have them for $60....Also the BOSCH OEM O2 sensor (list price of $350) can be had at Autozone for a mere $160...So forget about going to the F-dealer and paying thru the nose for the same OEM BOSCH O2 sensor...Get one thru your local Auto store for much less...

    Okay, on to troubleshooting the "Check Engine" problems....After reading the thread pointed out by Ernie above (thanks man!) on how to check the MAF sensor resistance, I measured both of mine and below are the results (photos tell the story).


    Soooo one of the MAF sensors has lower resistance than the other (379 vs 381 ohms)...Is that a problem or not???? I ths point I wasn't sure so I swapped the MAF sensors around and now I get the "Check Engine" light stay on the 1-4 bank only....BINGO!!

    It looks like one of the MAF sensors is on its way out...I'm not sure based on the resistance reading alone that the MAF sensor is bad or not but it certaintly seems to trigger the "Check Engine" light on my car and also give me the error code "1111"....No other changes were made prior to swapping the MAF sensors.

    That's all for now - All the best - VK
     
  3. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    29,272
    socal
    #28 fatbillybob, Jun 24, 2004
    VK,

    There is a little screw under the blue cap so you can dial into the 383 ohm magic# reported by Ferrarioldman on FC. I don't think that the resistence # alone is the problem. You are only off by 4 ohms or 1%. I do not think that will trigger the MIL. You may have something else going on either in the MAF or the wiring. But if tiy dial the drivers maf to 383 and it works then you have found the problem and taught us all something new.
     
  4. sdesjardins1985

    sdesjardins1985 Rookie

    May 13, 2015
    2
    #29 sdesjardins1985, May 13, 2015
    Hey guys did you know you have to reset the ecu after did a major service like timing belt at cold you disconnect the batterie they said 35 sec to 2 min after you start de vehicle for 10 min and it's important to not turn on everything of electronics just saying
     
  5. AceMaster

    AceMaster Three Time F1 World Champ

    Feb 6, 2009
    34,789
    Ontario, Canada
    Full Name:
    Mike
    #30 AceMaster, May 15, 2015
    Battery is disconnected during major.
     
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