Cadillac CTS 2013 Owner's Manual page 290

10-14 Vehicle Care
To inspect or replace the engine air
cleaner/filter:
1. Turn the ignition off.
2. Remove the side cover by
pulling up on the front of the
cover.
3. Disconnect the electrical
connector from the air box.
4. Loosen the screw on the clamp
holding the air outlet duct in
place. Do not remove the clamp.
Move the duct aside.
5. Remove the hose from the air
cleaner housing mounting arm.
Move the hose aside.
6. Remove the three air cleaner
housing cover screws.