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

Air filter removal/installation
A/c unit removal/installationMazda 6 Service Manual: Location index
INTAKE-AIR SYSTEM
FUEL SYSTEM
Engine Room Side
Fuel tank side
EMISSION SYSTEM
Engine room side
CONTROL SYSTEM
...
Mazda 6 Service Manual: Operating Tips for CD Player
Condensation phenomenon
Immediately after turning on the heater when the vehicle is cold, the CD or optical
components (prism and lens) in the CD player may become clouded with condensation.
At this time, the CD will eject immediately when placed in the unit. A clouded CD
can be corrected sim ...