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 playSpecial tools and equipment
Recommended service material
Note
required service material is also described in the following.
“Front brake components”
Special tool
...
Exhaust emission control system
description
The exhaust emission control system is composed of the pair system, exhaust
control system, ho2 sensor, threeway
catalyst system and isc system. The fresh air is drawn into the exhaust ports
through the pair control solenoid
valve and pair reed valves. The pair control solenoid valve is operat ...
Dtc “c36” (p1764), “c37” (p1765), “c38” (p1766) or “c39” (p1767): secondary
fuel injector circuit
malfunction
Detected condition and possible cause
Detected condition
Possible cause
Some failure exists in the fuel injector signal in a high
load, high revolution condition.
Injector circuit open or short.
Injector malfunction.
Ecm malfunction.
...