1. Disconnect the negative battery cable.
2. Remove the intake maniforld.(see INTAKE-AIR SYSTEM REMOVAL/INSTALLATION.)
3. Remove the PCV valve.
4. Blow through the valve and verify that air flows as specified.

Specification

Egr valve inspection
Three-way catalytic converter (twc) inspectionMazda 6 Service Manual: Drive Selection (Some models)
Drive selection is a system to switch the vehicle's drive mode. When the sport
mode is selected, vehicle's response against accelerator operation is enhanced.
This provides additional quick acceleration which may be needed to safely make maneuvers
such as lane changes, merging onto freeways, o ...
Mazda 6 Service Manual: Emission Control System
This vehicle is equipped with an emission control system (the catalytic converter
is part of this system) that enables the vehicle to comply with existing exhaust
emissions requirements.
WARNING
Never park over or near anything flammable: Parking over or near
anything flammable, such as dry ...