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Home >> Infiniti >> 2004 >> Q45 >> Repair and Diagnosis >> Engine Performance >> Engine Control System >> DTC P0171, P0174: Fuel Injection System Function >> Diagnostic Procedure >> 5. Check Fuel Pressure
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5. Check Fuel Pressure

  1. Release fuel pressure to zero. Refer to FUEL PRESSURE RELEASE  .
  2. Install fuel pressure gauge and check fuel pressure. Refer to FUEL PRESSURE CHECK  .
    1. At idling: 350 kPa (3.57 kg/cm 2 , 51 psi) 

OK or NG 

OK: GO TO 7. CHECK MASS AIR FLOW SENSOR .

NG: GO TO 6.