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O/T Ford Explorer CK Engine Light

Discussion in 'Uncategorized Threads' started by dr.t, Jun 7, 2008.

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  1. dr.t

    dr.t TS Member

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    Always good info on here even if off topic so I thought I would test any FORD Service Technicians who may be Trapshooters and enjoy this site as much as I do. Setting codes PO171/PO174, system adaptive fuel too lean banks one and two. Any thoughts on common cause or further diagnosis from FORD ahead. Thanks and Shoot well and shoot often.
     
  2. cmptrwz1

    cmptrwz1 TS Member

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    check fuel pressure at the rails on both sides at the correction thay look like tire value stems see manule for correct pressure if it is low could be bad fuel filter or bad fuel pressure regulator which is vacum controled or a fuel pump going bad if all pressure are ok then it may be a bad o2 sencer.
     
  3. bcnu

    bcnu Active Member

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    Or if you had just put some gas in the truck prior to the check engine light coming on you might try just twisting the gas cap a couple extra turns. Or you could call an Oreillys auto or your local ford dealer. John
     
  4. ljunatic

    ljunatic Member

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    Very often caused by an intake vacumm leak , especially cold or during warmup. Can be very tough to pinpoint. Often best found with a smoke test. Good luck
     
  5. emm2

    emm2 Member

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    Fuel filter, vacuum leak, dirty MAF sensor. All will cause this code. It is NOT a gas cap problem.
     
  6. Quack Shot

    Quack Shot Active Member

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    I'd be looking for unmetered air or a contaminated/malfunctioning MAF sensor. If you can get the freeze frame data and look at the RPM and fueltrim pids, that could give you a better indicator of whether it's a vacuum leak or not. Long Term Fuel Trims being too far positive at idle speeds and normal at speed would tend to indicate a vacuum leak. If they are off at load conditions other than idle as well, you would be looking at something that would affect the Air Fuel ratio across the board. That would probably be unmetered air (air induction leak) or a Mass Air Flow Sensor concern such as contamination of the hotwire. There is also a possibility that low fuel pressure, clogged injectors, clogged fuel filter, or an O2 sensor concern could be the root cause, but it's more common to have issues with the MAF. Even a small piece of dirt can throw the system off by a large amount and set those codes. A sharp tech and a scan tool can give you a good idea of what you are looking at.

    A dirty, improperly installed, or defective air filter can allow a lot of dirt to flow into the MAF. It's a very common issue. Make sure you use a quality replacement.

    You also might want to look at the air induction tube and check for oil contamination. If there is a lot of oil present, it could make the contamination issue worse if the oil migrates into the sendsor.
     
  7. kehrby

    kehrby Active Member

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    I'm assuming this is a 4.0l SOHC, approximately 1998-2003? If so intake gaskets are common for this.

    Steve
     
  8. dr.t

    dr.t TS Member

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    Well i guess if i put year and engine that would help. SORRY! Model year 2000/ 5.0 V8
     
  9. kehrby

    kehrby Active Member

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    5.0 did not commonly have intake gasket problems as much as the 4.0 did. It is definately a lean problem so any of the above mentioned fixes for lean problems should be checked. MAF, vacuum lines. Pcv valve and lines etc..

    Steve
     
  10. dr.t

    dr.t TS Member

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    Thanks to those that offered suggestions and possible cures, problem found is the EGR valve and EGR valve to exhaust manifold tube connection have rotted away and has created a severe vacuum leak. Shoot well and Shoot often, again thanks to those who offered any type of help.
     
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