P0300 FORD - Random Misfire Detected

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What does this mean?

Possible causes

  • Faulty spark plug (s)
  • Faulty ignition coil (s)
  • Clogged or faulty fuel injector (s)
  • Intake air leak
  • Fuel injectors harness is open or shorted
  • Fuel Injectors circuit poor electrical connection
  • Ignition coils harness is open or shorted
  • Ignition coils circuit poor electrical connection
  • Insufficient cylinders compression
  • Incorrect fuel pressure
  • Tech notes

    The P0300 code means that a cylinder(s) is misfiring or is randomly misfiring. Start by checking for intake leaks, intake gaskets are commonly caused by multi-cylinder misfiring. If no leak is found the next step is to replace the spark plugs. If the problem persists more tests needs to be done to diagnose problem, see "Possible Causes"

    2002 Expedition Misfire






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    When is the code detected?

    The random misfire DTC indicates multiple cylinders are misfiring or the powertrain control module (PCM)

    Possible symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Lack/loss of power
  • Hard start
  • Engine hesitation
  • P0300 Ford Description

    When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, the Engine Control Module (ECM) can determine that a misfire is occurring.
    OBDII Code P0300 Ford - Random Misfire Detected - Engine-Codes.com

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