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Home >> Subaru >> 2021 >> WRX STI >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics) (2.5L) (2 Of 4) >> Diagnostic Procedure with Diagnostic Trouble Code (DTC) >> DTC P0171: System Too Lean Bank 1 >> Diagnostic Method
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Diagnostic Method

Compare the diagnostic value with the threshold value, and if a condition meeting the malfunction criteria listed below continues for 10sx3 time(s) or more, judge that there is a fault in the fuel system.

JUDGMENT VALUE SPECIFICATION

Malfunction Criteria Threshold Value
Offset amount of main feedback compensation ≥1.35

time needed for diagnosis:  10sx3 time(s)

Malfunction indicator light illumination:  Illuminates when malfunction occurs in 2 continuous driving cycles.