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: Cargo compartment light switch inspection
1. Remove the liftgate lower trim. (See LIFTGATE LOWER TRIM
REMOVAL/INSTALLATION)
2. Disconnect the cargo compartment light switch connector.
3. Inspect for continuity between the cargo compartment light switch
terminals using an ohmmeter.
If not as specified, replace the liftgate lock.
...
Mazda 6 Service Manual: Parking brake (lever type) removal/installation
1. Remove the center console. (See CONSOLE REMOVAL/INSTALLATION.)
2. Remove the rear seat cushion (4SD) or rear seat (5HB) . (See REAR SEAT
REMOVAL/
INSTALLATION.)
3. Remove the exhaust pipe bracket.
4. Remove in the order indicated in the table.
5. Install in the reverse order of removal.
6 ...