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Home >> Subaru >> 2019 >> WRX STI >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics) (STI) (4 Of 4) >> Diagnostic Procedure With Diagnostic Trouble Code (DTC) >> DTC P2431: Secondary Air System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1 >> Diagnostic Method
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Diagnostic Method

If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.

Judgment value 

Malfunction Criteria Threshold Value
|Secondary air pipe pressure - Intake manifold pressure| > 7.9 kPa (59.44 mmHg, 2.3 inHg)

Time needed for diagnosis:  Less than 1 second

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