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Home >> Mitsubishi >> 2002 >> Eclipse GS, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self Diagnostics - 2.4L >> Diagnostic Tests >> DTC P0401: Exhaust Gas RECIRCULATION Flow Insufficient Detected >> Diagnostic Procedure
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Diagnostic Procedure

  1. Check the EGR system. See EXHAUST GAS RECIRCULATION (EGR) under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If a problem exists, repair and go to step  3. If the EGR system is functioning properly, go to next step.
  2. Connect scan tool to the data link connector. Start the engine and run at idle. Set the scan tool to data reading mode for item 95, Manifold Differential Pressure Sensor. Warm up the engine to normal operating temperature: 176-205°F (80-96°C). The pressure should be between 65-78 kPa when idling. Turn the ignition off. If the sensor is operating properly, clean the EGR valve and EGR passage and go to next step. If the sensor is malfunctioning, refer to DTC P1400.
  3. Carry out a test drive with the drive cycle pattern (OBD-II). See EGR MONITOR . Check the diagnostic trouble codes. If DTC P0401 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.
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