LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2021 >> Legacy Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (2.5L) (Diagnostics) (4 Of 4) >> Diagnostic Procedure With Diagnostic Trouble Code (DTC) >> DTC P2271: O2 Sensor Signal Biased/Stuck Rich Bank 1 Sensor 2 >> General Description >> Diagnostic Method
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Method

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

JUDGMENT VALUE SPECIFICATION

Malfunction Criteria Threshold Value
Output voltage of rear oxygen sensor More than 0.15V

Time needed for diagnosis:  500ms

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