High CO at High RPM

DEFINITION: Abnormally high Carbon Monoxide with low or normal Hydrocarbons during cruise (2500 rpm).


POSSIBLE CAUSE ACTION


Canister purge system Check Evaporative System.


[1][2]PCV malfunction Check PCV system.



Restricted exhaust Check for plugged exhaust system.


Incorrect Spark Advance Check Spark Controls (EST, ESC, etc...).


Fuel metering malfunction


Fuel Injection Check fuel pressure.
Perform injector balance test.
Inspect regulator operation
(check vacuum line and return hose),
Service Fuel Injectors (Pressure clean).