Cadillac 2009 STS-V - Manual (Page 349)

Engine Air Cleaner/Filter The engine air cleaner/filter is in the engine
compartment on the driver’s side of the vehicle,
near the front. See Engine Compartment Overview
on page 5-12 for more information on locating the
air cleaner/filter.
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter at the Maintenance II
intervals and replace it at the first oil change after
each 50,000 mile (80 000 km) interval. See Scheduled
Maintenance on page 6-4 for more information.
If you are driving in dusty/dirty conditions, inspect
the filter at each engine oil change.
4.6L V8 Engine shown, 3.6L V6 Engine similar
5-23