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: Exterior lighting system
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Mazda 6 Service Manual: Lane-keep Assist System (LAS) & Lane Departure Warning System (LDWS)
The Lane-keep Assist System (LAS) & Lane Departure Warning System (LDWS) alerts
the driver that the vehicle may be deviating from its lane and it provides steering
assistance to help the driver stay within the vehicle lanes.
The Forward Sensing Camera (FSC) detects the white lines (yellow l ...