High CO - at High RPM
This condition indicates abnormally high Carbon Monoxide with low or normal Hydrocarbons during cruise (2500 rpm).
POSSIBLE CAUSE ACTION
Faulty canister purge system Check Fuel Evaporative System
[1][2]PCV malfunction Check PCV system
Restricted exhaust Check Catalytic Converter
Incorrect Spark Advance Check Spark Controls,
Fuel Injection malfunction Check fuel pressure
Perform injector balance test
Inspect regulator operation
(check vacuum line and return hose),
Service Fuel Injectors (Pressure cleaner)
EGR malfunction Check EGR system.