Subaru 2009 IMPREZA Service Manual page 778

Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AF:DTC P0137 O2 SENSOR CIRCUIT LOW VOLTAGE (BANK 1 SENSOR 2)
1. OUTLINE OF DIAGNOSIS
Detect continuity NG of the oxygen sensor. If the oxygen sensor voltage reading is not within the probable
range considering the operating conditions, judge as NG.
2. COMPONENT DESCRIPTION
(3)
V
(2)
(A) Electromotive force
(D) Lean
(1) Atmosphere
(1)
(2)
(B) Air fuel ratio
(E) Theoretical air fuel ratio
(2) Exhaust gas
GD(H4SO)-54
(E)
(A)
(C) (B)
(C) Rich
(F) Comparative voltage
(3) Electromotive force
(F)
(D)
EN-01696