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Home >> Subaru >> 2004 >> Baja Base, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Diagnostic Trouble Code (DTC) Detecting Criteria (H4SO) >> Diagnostic Trouble Code (DTC) Detecting Criteria >> DTC P0171: System Too Lean (Bank 1) >> Diagnostic Method
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Diagnostic Method

Judge that the malfunction occurred in fuel system when the malfunction criteria are completed for 50 seconds or more by comparing the diagnostic value (fsobd) with threshold value.

Judgment Value 

Fig 1: Threshold Value Table (1 Of 3)
G00898628Courtesy of SUBARU OF AMERICA, INC.

Map 2: Threshold value for fuel system malfunction criteria 

Fig 2: Threshold Value Table (2 Of 3)
G00898629Courtesy of SUBARU OF AMERICA, INC.
  1. Time Needed for Diagnosis: 

    10 seconds X 5 times

  2. Malfunction Indicator Light Illumination: 

    2 continuous driving cycles.

Judge OK when the malfunction criteria below are completed for 10 seconds or more.

Judgment Value 

Fig 3: Threshold Value Table (3 Of 3)
G00898630Courtesy of SUBARU OF AMERICA, INC.