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: Lane Departure Warning
If the system determines that the vehicle may deviate from its lane, the lane
departure warning (beep sound, rumble sound*1, or steering wheel vibration) is activated
and the direction in which the system determines that the vehicle may deviate is
indicated in the multi-information display and ...
Mazda 6 Service Manual: Throttle position (tp) sensor inspection
Note
Perform the following inspection only when directed.
Resistance Inspection
1. Perform the following test only when directed.
If as specified but TP PID value is out of specification, inspect
resistance of TP sensor.
If not as specified, inspect the following:
- Accelerato ...