Subaru Legacy 2005 Service Manual page 1306

ENGINE (DIAGNOSTICS)
DTC
P2138 Throttle/Pedal Position Sensor/
Switch "D"/"E" Voltage Correlation
P2228 Barometric Pressure Circuit Low
P2229 Barometric Pressure Circuit High
List of Diagnostic Trouble Code (DTC)
Item
<Ref. to EN(H4DOTC)(diag)-208, DTC P2138 THROTTLE/PEDAL POSI-
TION SENSOR/SWITCH "D" / "E" VOLTAGE CORRELATION, Diagnostic
Procedure with Diagnostic Trouble Code (DTC).>
<Ref. to EN(H4DOTC)(diag)-212, DTC P2228 BAROMETRIC PRESSURE
CIRCUIT LOW, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
<Ref. to EN(H4DOTC)(diag)-212, DTC P2229 BAROMETRIC PRESSURE
CIRCUIT HIGH, Diagnostic Procedure with Diagnostic Trouble Code
(DTC).>
EN(H4DOTC)(diag)-66
Reference