1. Remove the VAD check valve (one-way). (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION)
2. Blow through A and verify that air flows from B.
3. Blow through B and verify that air does not flow from A.

Variable air duct (vad) control solenoid valve inspection (l3)
Idle air control (iac) valve inspectionMazda 6 Service Manual: Fuel Gauge (Without Multiinformation Display)
The fuel gauge shows approximately how much fuel is remaining in the tank when
the ignition is switched ON. We recommend keeping the tank over 1/4 full.
If the low fuel warning light illuminates or the fuel level is very low, refuel
as soon as possible.
Refer to Warning Lights.
NOTE
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Mazda 6 Service Manual: Front upper arm inspection
1. Remove the upper arm from the vehicle.
2. Inspect for damage, cracks, and bending.
3. Inspect the ball joint rotation torque.
(1) Rotate the ball joint five times.
(2) Measure the rotation torque using a suitable allen socket and a
torque wrench.
If not within the specification ...