Adjust the engine idle speed periodically on the engine at normal operating temperature.
To adjust the idle speed:

Engine oil and filter change
Throtile cable playCrankcase emission control system
description
The engine is equipped with a pcv system to prevent discharging crankcase
emissions into the atmosphere. Blow-by
gas in the engine is constantly drawn into the crankcase, which is returned to
the combustion chamber through the
pcv (breather) hose, air cleaner and throttle body.
...
DTC “c46” (p1657-h/l or p1658): excv
actuator circuit malfunction
Detected condition
Possible cause
C46
The operation signal does not reach the
excv actuator.
Excva position sensor voltage low or
high
0.14 V ≤ Sensor voltage < 4.9 V
(without the above range)
excva can not operate properly.
Excva ...
Crankshaft thrust clearance inspection and
selection
Refer to “engine bottom side disassembly” (page 1d-
49).
Refer to “engine bottom side assembly” .
Inspection
With the crankshaft’s right-side and left-side thrust
bearings inserted into the upper crankcase.
Measure the thrust clearance “a” between the leftside
thrust bearing and ...