Owners of other Mazda vehicles such as the CX-5, CX-3, CX-30, MX-30, CX-8, Mazda8 (MPV), MX-5 Miata, Mazda2 (Demio), Mazda3 (Axela), Mazda6 (Atenza) and Mazda5 (Premacy) may also find these DIY instructions to be helpful.

A few compatible replacement air filters for the Skyactiv-G 2.5L turbocharged I4 engine with their part numbers are as follows: EcoGard XA10597, Mazda PY8W133A0 (also known as PY8W-13-3A0) and K&N 33-3024.

No tools are needed to access and replace the filter.

A wet/dry shop vacuum can be useful for cleaning out the bottom of the air box or cleaning the old filter to re-use it.

The first two steps are to open the hood and then move to the right (driver) side of the engine bay.

The rectangular shaped black plastic engine air filter housing is located just behind the driver side headlight assembly and in front of the electrical fuse box and the 12V battery.

There are two metal latches that secure the two halves of the air box together.

One latch is located near the front right corner of the box. The second latch is situated by the front left corner of the box.

The latches should remain attached to the bottom half of the air filter housing.

You may need to pull the air box cover forward to dislodge the two tabs on the rear edge from their slots.

The OEM (original equipment manufacturer) air filter in this 2019 CX-9 AWD was marked as part number Mazda SH01-133A0 K8800.

Inspect both sides of the old air filter.

If the old filter is dark grey or black and clogged with dirt, dust, sand, hair, insects, pollen, leaves and soot, it should be replaced with a new element.

I recommend buying the EcoGard XA10597 engine air filter since it has excellent reviews on Amazon from other CX-9 owners.

If the old filter is relatively clean, just tap out the large debris and remove any fine dust with a vacuum.

Lower the new filter into the bottom half of the air box.

The pleats should be facing down and the rubber gasket should be facing up towards you.

Line up the two plastic tabs on the rear edge of the cover with their corresponding slots on the bottom half of the air box.

Slide the tabs into the slots.

Close the front edge of the air box cover.

Snap the latches back into place to secure the two halves of the air filter housing together.

Make sure that the two halves of the assembly are flush together at every edge with no part of the filter visible.

Don't forget to write down the filter change in your vehicle's service records.

According to the 2019 Mazda CX-9 owner's manual, the service interval specification for changing the engine air filter is every 22,500 miles (36,000 km) or at least every 36 months (3 years).

For more, please check out all of the 2016-2021 Mazda CX-9 DIY Repair & Maintenance Guides.