The most reasonably priced component used on the Civic 2004 (4) 2dr Ex (ka) Duct is the Screw,tapping,(po)4x.
The six Civic 2004 (4) 2dr Ex (ka) Duct component parts are all listed in this schematic.
On this parts fiche the Screw,tapping,(po)4x is the most specified component.
