Subaru LEGACY 2004 Service Manual page 784

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
7 CHECK POOR CONTACT.
Check poor contact in purge control solenoid
valve connector.
Check
Is there poor contact in purge
control solenoid valve connec-
tor?
EN(H4SO 2.5)(diag)-168
Yes
Repair the poor Replace the ECM.
contact in purge <Ref. to FU(H4SO
control solenoid 2.5)-36, Engine
valve connector. Control Module
(ECM).>
No