Maintaining my Porsche 911 (991 generation) is key to ensuring a clean and comfortable driving experience. This process will also work on these other models:
Porsche 911 -Type 991 (2012-2019)
Cayman/Boxter - Type 981 (2012-2016)
Cayman/Boxter - Type 718 (2016-Present)
One often-overlooked maintenance item is the cabin air and pollen filter. Replacing it regularly keeps the air inside your car fresh and helps your HVAC system function efficiently. Fortunately, swapping out the cabin filters on this 991 is a straightforward DIY task and it will save you several hundred dollars. Follow along on my guide and you will be done in 10minutes or less.
Tools and Parts Needed:
- Two cabin air filters
Internal Filter: 991-572-371-00
- Flathead screwdriver (or a simple quarter)
- Trim removal tool (optional but helpful)
- Flashlight (for better visibility)
Step 1: Locate the Cabin Filter Housing
The Porsche 991 has two cabin air filters, located in the passenger footwell under the dashboard. You’ll need to access the area beneath the glovebox to get started, which can be done using either a simple quarter or a flathead screwdriver.
Step 2: Remove the Under-Dash Cover
Using a flathead screwdriver (but the quarter actually fits best), remove the three plastic screws securing the under-dash panel.

Carefully lower the panel, taking note of any attached wiring harnesses (such as the footwell light). If necessary, disconnect the harness to fully remove the cover.
Step 3: Remove the Cabin Filter Cover
Once the under-dash cover is out of the way, locate the rectangular cabin filter housing.
Slide the cover off by releasing the clips or tabs securing it. This can be easily done with your fingers and just popping it off and it will swing down from passenger side towards the drive side.
Step 4: Remove the Old Cabin Filters
The filter is squished a bit in there so just pull it out the bottom.
Take note of the airflow direction indicated on the old filters, as you’ll need to install the new ones in the same orientation. TIP The words are closer to the passenger side
Step 5: Install the New Cabin Filters
Insert the new filter by angling it upward and sliding it into place. You might have to squeeze it tother a bit.
Push it up to ensure it can fully expand into position. I give it a finger bump or two.
Ensure filter is seated correctly and in the proper airflow direction.
Step 6: Reassemble Everything
Reattach the filter cover by securing the clips or tabs.
Reinstall the under-dash panel (reconnecting any wiring if necessary)
Secure the panel with the tool of your choice.
Now lets move to the Front Exterior Pollen Filter
Tools & Parts Needed:
• New pollen filter (I have them listed in my Amazon Store)
• Plastic trim removal tool (optional)
So lets do this step-by-step:
Step 1: Open the Front Trunk (Frunk)
Pop open the frunk.
Locate the plastic cowl panel at the base of the windshield and remove in the back passenger corner is the L shaped pollen filter housing.
Step 3. Remove the Old Filter
You’ll see the pollen filter in a plastic tray.
Unclip the filter cover and slide out the old filter. Again note the direction of the writing on the side specifically the triangle towards the top.
Step 4. Install the New Filter
Insert the new filter with the airflow direction arrows pointing the same way as the old one. That triangle should be pointing towards the back of the car.
Ensure it sits properly in the tray.
Step 5. Reassemble Everything
Clip the filter cover back on.
Reattach the plastic cowl cover
Reinstall the rubber seal along the edge of Frunk so it overlaps the plastic cowl cover.
Final Check
Close the frunk and start the car and test the HVAC system to ensure proper airflow. If everything is functioning normally, you’re good to go!
Conclusion
Replacing the cabin air filters in your Porsche 991 is a simple yet essential maintenance task. By doing it yourself, you save money and keep your car’s interior air fresh. Refer to the owner’s manual for recommended replacement intervals, but typically, it’s best to change them every 15,000 to 20,000 miles or once a year.
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