360 P0174 | FerrariChat

360 P0174

Discussion in 'Technical Q&A' started by ferrari-guy, Jul 9, 2011.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. ferrari-guy

    ferrari-guy Rookie

    Aug 5, 2007
    44
    Canada
    Need some tech advice please.

    I have had an ongoing rough idle on my 03/360- CEL has come on 2 X - both times scanned with OBD2 with code P0174. `bank 2 running lean`

    I`m ready to clean the MAF sensor as the probable solution. I have secured the special torx bit (t25 btw, not t20 as maybe the myth) and CRS MAF cleaner.

    Q:
    - which side in bank 2? (ie: which MAF sensor should be cleaned?)
    - tips or tricks to un-plug the sensor without damage to the wiring harness?

    thanks
     
  2. brian.s

    brian.s F1 Rookie
    Professional Ferrari Technician

    Nov 3, 2003
    3,809
    Midwest
    Full Name:
    Brian
    #2 brian.s, Jul 10, 2011
    Last edited: Jul 10, 2011
    More likely to be a vacuum leak........

    You need to monitor the O2 sensor voltages, smoke test the intake. But, it can be from the MAF sensor, on a 360 I would expect a code on each bank if that were the case....
     
  3. lndshrk

    lndshrk Formula Junior

    Nov 7, 2003
    753
    SLC, Utah
    Full Name:
    Jim Conforti
    Clear codes - car off - wait 5 min - swap MAF's from side to side - does code come back on the OPPOSITE side?

    If so, suspect MAF

    If not, suspect something else.
     
  4. ferrari-guy

    ferrari-guy Rookie

    Aug 5, 2007
    44
    Canada
    Might try the swap from side to side and see if the code reappears for left bank. thanks
     
  5. ferrari-guy

    ferrari-guy Rookie

    Aug 5, 2007
    44
    Canada
    #5 ferrari-guy, Jul 12, 2011
    Last edited by a moderator: Sep 7, 2017
    On advice from this forum, ive tried to carefully scan the engine bay for any signs of a vacuum leak and have found the rubber hose inlet that bridges between the throttle body and intake manifold to be kinked and not fully clamped against the flange...could this be the cause of the "running lean condition" and the P0174 code. I was prepared to clean the MAF's but have held off...advice please.
    Image Unavailable, Please Login
    Image Unavailable, Please Login
    Image Unavailable, Please Login
     
  6. EMI-SC

    EMI-SC Karting

    Aug 2, 2008
    113
    Full Name:
    Chris Felber
    Fix the obvious first. Could def. be the problem
     
  7. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    29,018
    socal
    Test it! propane torch not lit, run gas right in front of the hole. Listen for change in idle. No change = that's not the problem
    change = there's your vacuum leak
     
  8. brian.s

    brian.s F1 Rookie
    Professional Ferrari Technician

    Nov 3, 2003
    3,809
    Midwest
    Full Name:
    Brian
    That will be it.....
     
  9. ferrari-guy

    ferrari-guy Rookie

    Aug 5, 2007
    44
    Canada
    thanks - will attempt repair
     
  10. Europeanroadandracing

    Europeanroadandracing South Carolina
    Professional Ferrari Technician

    Dec 19, 2003
    2,228
    Isle of Palms, SC
    Full Name:
    Karl Troy
    That's where your unmetered air is coming from.
     
  11. Ingpr

    Ingpr F1 Rookie

    Jun 30, 2009
    2,619
    PR
    Full Name:
    David
    1+
    also use a hose with the propane and get it as closer you can on the head gaskets with the manifold.
     
  12. ferrari-guy

    ferrari-guy Rookie

    Aug 5, 2007
    44
    Canada
    Update
    - removed air intake hose and installed it properly with new clamps...reset CEL...drove it for 50km +/- ... CEL is back.

    -Next step- MAF clean...to be continued.
     
  13. brian.s

    brian.s F1 Rookie
    Professional Ferrari Technician

    Nov 3, 2003
    3,809
    Midwest
    Full Name:
    Brian
    The code is triggered as a result of a problem. That initial problem can have other effects. Consider that the air leak may contribute to a full enrichening of the mixture which could then pollute an oxygen sensor, which could.......etc., etc..

    Diagnostics involve more than just reading off a number, it could be showing an effect rather than the problem. the car should be monitored to try and pinpoint the problem better. you may have fixed the original problem and now are chasing the secondary result.
     

Share This Page