Subaru 2009 IMPREZA Service Manual page 207

Drain Filter
EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES)
12.Drain Filter
A: SPECIFICATION
The drain valve is a non-disassembled part, so do
not remove the drain filter from drain valve. Refer to
"Canister" for removal and installation procedures.
<Ref. to EC(H4SO)-5, REMOVAL, Canister.>
<Ref. to EC(H4SO)-7, INSTALLATION, Canister.>
EC(H4SO)-17