2013 Subaru Impreza Owner's Manual - Page 383

Maintenance and service 11-13 3. Loosen the screw on the clamp and pull the air intake boot out of the air cleaner case. 4. Unsnap the two clips holding the air cleaner case cover. Spark plugs It may be difficult to replace the spark plugs. It is recommended that you have the spark plugs replaced by your SUBARU dealer. The spark plugs should be replaced according to the maintenance schedule in the "Warranty and Maintenance Booklet". CAUTION 7. To install the air cleaner case, insert the three projections on the air cleaner case into the slits on the air cleaner case cover. 8. Install in the reverse order of removal. 5. Open the air cleaner case and remove the air cleaner element. 6. Clean the inside of the air cleaner case and case cover with a damp cloth and install a new air cleaner element. Make sure the cables are replaced in the correct order. & Recommended spark plugs For the recommended spark plugs, refer to "Electrical system" F12-7.