troubleshooting CEL P0171

Discussion in '96-04 - 4V Specific' started by scarface, Apr 11, 2007.

  1. scarface

    scarface Guest

    I dont have any vacuum leaks, and my MAF sensor is clean.

    I did notice however a pretty good exhaust leak on the passenger side manifold/xpipe joint.... you think that could cause this code? Maybe the o2 sensor isnt reading correctly because of it? I noticed the leak after the clutch install, and thats when the code came on too.

    any thought?
     
  2. blackfang

    blackfang Active Member

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    An exhaust leak will cause a lean condition being there is more air added now. I would fix that leak first, then reset the ecu and see if it changes.
     
  3. 97blackgt

    97blackgt Well-Known Member

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    This Pinpoint Test is intended to diagnose the following:

    Heated Oxygen sensor (HO2S) /Heater
    HO2S Connections
    Vacuum Systems
    Fuel Injector(s)
    Harness Circuits: HO2S GND, HO2S, INJ 1-8, VPWR and SIG RTN
    Powertrain Control Module (PCM)

    check intake/ PCV valve
    MAF valve
     
  4. blackfang

    blackfang Active Member

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    I say fix the leak in the exhaust first and see what that does before trying to find other concerns. Go with the obvious first.
     
  5. scarface

    scarface Guest

    thanks guys...Ive checked everything on that list. Its all in working order.

    I have bought the gasket, should be here tomorrow. Im confident it is that though. It started right after I removed the xpipe to fix my clutch. no leak before, no CEL before.

    now leak, and CEL.

    I will report back.
     
  6. 97blackgt

    97blackgt Well-Known Member

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    hopwfully it fixes it man...let us know
     
  7. scarface

    scarface Guest

    thanks I will :D
     
  8. 97blackgt

    97blackgt Well-Known Member

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    any ideas yet scarface...funny thing is i now have a check engine light also, wich i think is due to an exhaust leak on the passenger side manifold. When i trying to take the x pipe off i stripped the nut, and now only one nut is holding the manifold and the x pipe together. I think it is the leak which is causing the problem, just wondering if u fixed yours yet?
     
  9. scarface

    scarface Guest

    I havent fixed it yet...I did get the gasket, but Im sure it is the problem...it all happened too close to be coincidence.
     
  10. 97blackgt

    97blackgt Well-Known Member

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    how much did the gasket cost you and where did u get it...i might also have to invest in one.
     
  11. scarface

    scarface Guest

    14 shipped from Randy at modular depo...got it in 1 day! :)
     
  12. 97blackgt

    97blackgt Well-Known Member

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    do you think the ford dealership would have them in stock? and a ballpark for the price?
     
  13. scarface

    scarface Guest

    yeah, but Randy is a ford dealership, and he sells at cost. probably around 14 bux or so.
     
  14. 97blackgt

    97blackgt Well-Known Member

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    ohhh i got ya...should be fixing mine tomorrow as long as i can get my car to the auto building...supposed to get 8-12 inches of snow :eek: :(
     
  15. scarface

    scarface Guest

    yeah it sucks...we have gotten 3 inches of rain today!
     
  16. scarface

    scarface Guest

    the gasket fixed my problem :)
     
  17. 97blackgt

    97blackgt Well-Known Member

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    fixed mine also....i forgot to post though

    now i have another CEL for an 02 sensor :-\ :nonono:
     
  18. blackfang

    blackfang Active Member

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    Glad to hear it ;)