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2000 Cadillac DeVille Question: Mutiple cylinder misfire

 

Question

lincdog2002, East Orange, NJ, August 25, 2009, 18:25
 Rookie

I have a problem the car runs fine until it warms up then it runs with a mis when I hooked up the code meter it told me that both banks of cylinders were burning lean and I had random cylinder misfire can anyone help me solve this problem

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  • Answer #1

    Bret Bodas from RepairPal Test Shop, August 25, 2009, 22:14
     Master

    Look for a large air leak in the intake hoses and pipes. Beyond that, you need to get into diagnosing the fuel injection system, which involves special tools and experience. If you have a voltmeter you can do some checks, do you have one?

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  • Answer #2

    August 25, 2009, 23:14
     Master

    What are the trouble codes that you retrieved?

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    lincdog2002, August 26, 2009, 12:10
     Rookie

    The trouble codes that I recieved were P0300,P171,P174 Random Cylinder misfire and lean burn conditions on bank one and bank two cylinders ,I also removed the engine cover and I could hear some air sounding like a leak and also have a volt meter

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    backyard tech, August 26, 2009, 16:28
     Master

    Vehicle Application: 2002 Cadillac Deville 4.6L

    Customer Concern: Rough idle, misfire. Powertrain Control Module (PCM) codes: P0171, P0174, P0300. OK at higher RPM. The throttle body boot was leaking.
    Tests/Procedures: 1. Check for vacuum leak at the boot between the throttle body and the upper intake manifold plenum.

    2. Spray water on the upper intake manifold, check for RPM response.
    Potential Causes: Intake Manifold Gaskets
    Throttle Body Boot

    Tech Tips: A new throttle body boot fixed.
    Diagnostic Codes: P0171, P0174, P0300

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  • Answer #3

    Visitor, August 17, 2010, 13:34

    check to see if your belt tensioner is moving at all when the engine is running if so you need a new one. its easy to change. when its loose its sortof throwing off your timing causing a random misfire and hesitation.

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  • Answer #4

    November 03, 2010, 17:36
     Rookie

    Change all you Spark plugs.

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