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

Air filter removal/installation
A/c unit removal/installationMazda 6 Service Manual: No.4 air intake mode does not change
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while performing the inspection to discover
whether poor contact points are the cause of any intermittent malfunctions.
If there is a problem, check to make sure connectors, terminal ...
Mazda 6 Service Manual: Symptom troubleshooting
Verify the symptoms, and perform troubleshooting according to the
appropriate number.
Vehicles with ABS/TCS
Vehicles with DSC
*1 : DSC system contains traction control function, DSC indicator light goes
on and off while DSC operates.
*2 : DSC indicator light goes on and off while D ...