2019 Subaru STI S209 Air Filter: Specs & Service

The housing is part of the engine intake path for the 2.5-liter flat-four engine. The cabin air filter is located separately, typically behind the glove box, and cleans air entering the passenger compartment. Mike Shaw Subaru in Thornton can inspect both locations during one service visit.

• Engine filter: intake housing in the engine bay
• Cabin filter: typically behind the glove box
• Service includes inspection of the intake path

These filters perform different jobs and are checked separately. A restricted engine filter can affect airflow to the 2.5-liter engine, while a loaded cabin filter can contribute to weak ventilation airflow or a dusty, musty smell. Both filters can be inspected during the same visit in Thornton.

• Engine filter supports clean combustion airflow
• Cabin filter supports HVAC and passenger air quality
• Each filter requires its own inspection and replacement

A visibly grey or debris-packed filter can confirm that airflow is restricted when the housing is opened. Engine-side symptoms may include reduced response, while cabin-side symptoms may point to the filter behind the glove box. Mike Shaw Subaru checks the engine and cabin filters together.

• Drop in fuel economy
• Duller throttle response
• Dusty or musty ventilation odor

Replacing either filter requires using the correct part for the engine and checking that the housing and intake path are properly seated afterward. A dealership visit adds inspection of both filters in one appointment, along with an intake-path check. This approach can help identify a filter problem affecting drivability or ventilation.

• Engine filter access is in the engine bay
• Cabin filter access is typically behind the glove box
• Both filters can be checked in one visit

The technician inspects the engine air-filter housing and intake path, then checks the cabin air filter. Replacement is performed with a filter matched to the engine’s specification, and both filters can be addressed during the same visit at Mike Shaw Subaru in Thornton. The service focuses on restoring clean airflow for the engine and cabin.

• Engine air-filter housing inspection
• Cabin air-filter and intake-path inspection
• Correct-part replacement for both filters

The STI S209 uses a 2.5-liter flat-four engine producing 341 horsepower and 330 lb-ft of torque. Clean intake airflow supports the engine’s operation, while a clean cabin filter supports ventilation airflow for occupants. Filter inspection is useful when fuel economy or throttle response changes.

• 2.5-liter flat-four engine
• 341 horsepower
• Required premium unleaded fuel

The service covers the engine air filter and cabin air filter in one visit. Technicians inspect the engine filter housing, intake path, and cabin filter before replacing filters with the correct part. Use the schedule appointment page to arrange service.

• Location: 1650 W 104th Avenue, Thornton, CO 80234
• Dealer: Mike Shaw Subaru
• Phone: 720-724-9280

Inspection is appropriate when fuel economy drops, throttle response feels duller, ventilation airflow weakens, or a dusty or musty odor develops. Road conditions and debris can also affect filter condition. Mike Shaw Subaru can check both filters against the vehicle’s maintenance needs during a scheduled visit.

• Inspect the engine filter and housing
• Inspect the cabin filter and intake path
• Replace filters when their condition requires it

Because this vehicle has a 2.5-liter flat-four engine, clean intake airflow matters for everyday drivability and throttle response. A restricted filter can reduce airflow and contribute to lower fuel economy. Since there is no stated manufacturer replacement interval for this model year, condition-based inspection is the practical focus. Schedule service at Mike Shaw Subaru or call 720-724-9280 for assistance.

Visit Mike Shaw Subaru at 1650 W 104th Avenue, Thornton, CO 80234 for air filter service and a check of both filter locations.

The cabin air filter and its intake path are then inspected. A filter contributing to a dusty or musty smell, or reduced ventilation airflow, can be replaced during the same visit. This combined process helps address engine airflow and passenger-compartment airflow together rather than treating them as the same component. Mike Shaw Subaru also provides a single booking for both filter checks and replacement with the correct parts.

Schedule service at Mike Shaw Subaru in Thornton or call 720-724-9280.

There is no stated manufacturer replacement interval for this model year, so inspection should focus on condition and symptoms. A drop in fuel economy or duller throttle response can indicate restricted engine airflow. A dusty or musty smell from the vents can point to the cabin filter, while a grey or debris-packed filter confirms the need for attention when the housing is opened.

Bring your 2019 Subaru STI S209 to Mike Shaw Subaru in Thornton for correct-fit filter service — schedule service.