1. Remove the vacuum hose..
2. Verify that air can be blown from the power brake unit side of the vacuum hose towards the vacuum pump side, and that air cannot be blown in the opposite direction.

If there is any malfunction of the inner check valve, replace it together with the vacuum hose as a single unit.
Vacuum Hose Removal/Installation
Vacuum Pump InspectionSide Air Bag Module Removal/Installation [Standard Deployment Control System]
WARNING:
Handling the air bag module improperly can accidentally operate (deploy)
the air bag module, which may seriously injure you. Read the air bag system
service warnings and cautions before handling the air bag module..
If the side air bag module is installed with debris i ...
Ion Sensor
Purpose/Function
Detects ion generation in the combustion chamber for detecting pre-ignition.
Detects ions which occur due to fuel combustion as current by applying bias
voltage to the spark plug, which is amplified in the ignition coil internal
circuit and input to the PCM.
...
Rear Drive Shaft Removal/Installation
CAUTION:
Performing the following procedures without first removing the ABS wheel?speed
sensor may possibly cause an open circuit in the harness if it is pulled by
mistake. Before performing the following procedures, remove the ABS wheel?speed
sensor (wheel side) and fix it to an ap ...