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