If there are notches worn into the splines, replace the sub clutch hub. Also, replace the steel plates if their teeth are damaged.

Clutch Housing Finger Inspection
Damper Cam InspectionExploded View
AL: Tighten the two clamp bolts alternately two times to ensure even
tightening torque.
G: Apply grease.
R: Replacement Parts
G: Apply grease.
L: Apply a non-permanent locking agent.
R: Replacement Parts
Specifications
...
Exhaust Butterfly Valve Actuator Resistance Inspection
Turn the ignition switch to OFF.
Disconnect the exhaust butterfly valve actuator lead connector
(2 pins connector) [A].
Set the hand tester to the × 1 Ω range and connect it to
the exhaust butterfly valve actuator connector.
Special Tool - Hand Tester: 57001-1394
Measure ...
Intake Air Pressure Sensor #1 Removal
NOTICE
Never drop the intake air pressure sensor #1 especially
on a hard surface. Such a shock to the sensor
can damage it.
Remove:
Air Cleaner Housing (see Air Cleaner Housing Removal
in the Fuel System (DFI) chapter)
Intake Air Pressure Sensor #1 Connector [A]
Remove the intake air ...