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Home >> Subaru >> 2017 >> WRX STI >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System (Diagnostics) (P000A To P015B) (2.5L) >> Diagnostic Procedure with Diagnostic Trouble Code (DTC) >> DTC P014C A/F/O2 Sensor Slow Response - Rich To Lean Bank 1 Sensor 1 >> Diagnostic Method 2
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Diagnostic Method 2

Detect the malfunction by the cumulative value obtained from the amount of variation in λ change.

Fig 1: Sensor Output - Diagnostic Method 2
G08317431Courtesy of SUBARU OF AMERICA, INC.

Judge as NG when the following conditions are established.

JUDGMENT VALUE SPECIFICATION

Malfunction Criteria Threshold Value DTC
Cumulative value obtained from the amount of variation in λ change < Value from Map P014C and P014D
MAP SPECIFICATION

Cumulative value obtained from the amount of variation in λ 0.00 6.00
Cumulative value obtained from the amount of variation in λ change 0.00 6.50

Time Needed for Diagnosis:  90000 ms

Malfunction Indicator Light Illumination:  Illuminates when malfunction occurs in 2 continuous driving cycles.