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: Antilock Brake System (ABS)
The ABS control unit continuously monitors the speed of each wheel. If one wheel
is about to lock up, the ABS responds by automatically releasing and reapplying
that wheel's brake.
The driver will feel a slight vibration in the brake pedal and may hear a chattering
noise from the brake system ...
Mazda 6 Service Manual: Rear wiper motor inspection
1. Disconnect the negative battery cable.
2. Remove the liftgate lower trim. (See LIFTGATE LOWER TRIM
REMOVAL/INSTALLATION)
3. Disconnect the rear wiper motor connector.
4. Connect battery positive voltage to the rear wiper motor terminal A and
the ground to a bare metal part of the vehicle a ...