1. Remove the air filter.
2. Inspect the air filter.
Note

Air filter removal/installation
A/c unit removal/installationMazda 6 Service Manual: Declaration of Conformity
Keyless Entry System/Immobilizer System
Blind Spot Monitoring (BSM) System
NOTE
During printing time of this user manual the approvals listed above are granted.
WARNING
Change or modifications not expressively approved by the party responsible
for compliance could void the use's authori ...
Mazda 6 Service Manual: Scheduled Maintenance (U.S.A., Canada, and Puerto Rico)
Follow Schedule 1 if the vehicle is operated mainly where none of the following
conditions (severe driving conditions) apply.
Repeated short-distance driving
Driving in dusty conditions
Driving with extended use of brakes
Driving in areas where salt or other corrosive materials are used
...