If they appear damaged or deteriorated, replace them.

Balancer Adjustment
Torque LimiterWhat Am I Responsible For?
You are responsible for maintaining your vehicle according to the maintenance
schedule shown in this owner’s manual.
You are responsible for notifying your dealer immediately if there is a problem,
and you, as the owner, will need to authorize the dealer to inspect the unit.
You will be re ...
Idle Speed Control Valve Actuator Removal
NOTICE
Never drop the idle speed control valve actuator especially
on a hard surface. Such a shock to the actuator
can damage it.
Remove:
Throttle Body Assy (see Throttle Body Assy Removal in
the Fuel System (DFI) chapter)
Idle Speed Control Valve Actuator Retainer Screws [A]
Idle Spe ...
Seat Cutter Operation Care
1. This valve seat cutter is developed to grind the valve for
repair. Therefore the cutter must not be used for other
purposes than seat repair.
2. Do not drop or shock the valve seat cutter, or the diamond
particles may fall off.
3. Do not fail to apply engine oil to the valve seat cutter
...