Subaru Legacy 2002 Service Manual page 760

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
1 CHECK ANY OTHER DTC ON DISPLAY.
Step
Does the Subaru Select
Monitor or OBD-II general
scan tool indicate DTC
P0122 or P0123?
EN-243
Check Yes
Inspect DTC
P0122 or P0123
using "17. List of
Diagnostic
Trouble Code
(DTC)". <Ref. to
EN-82, List of
Diagnostic
Trouble Code
(DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P1142.
Engine (Diagnostics)
No
Replace throttle
position sensor.
<Ref. to FU-34,
Throttle Position
Sensor.>