Subaru 2009 IMPREZA Service Manual page 1566

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
EA:DTC P2431 SECONDARY AIR INJECTION SYSTEM AIR FLOW /PRESSURE
SENSOR CIRCUIT RANGE/PERFORMANCE
DTC DETECTING CONDITION:
• Detected when two consecutive driving cycles with fault occur.
• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-225, DTC P2431 SECONDARY AIR INJECTION SYS-
TEM AIR FLOW /PRESSURE SENSOR CIRCUIT RANGE/PERFORMANCE, Diagnostic Trouble Code
(DTC) Detecting Criteria.>
CAUTION:
After servicing or replacing faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-54,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H4DOTC)(diag)-43, PROCE-
DURE, Inspection Mode.>.
EN(H4DOTC)(diag)-345