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 bowl vent/canister purge system Check evaporative system



[1][2]PCV malfunction Check PCV system



EGR malfunction Check EGR system


Restricted exhaust Check catalytic converter



Incorrect Spark Advance Check spark controls (EST ESC)



Verify vehicle remains in Perform Self-Diagnostic procedures
Closed Loop at steady throttle
(2500 rpm) and oxygen sensor
is working




Fuel metering malfunction Check fuel pressure
Perform injector balance test
Inspect regulator operation
(check vacuum line and return hose),
Service Fuel Injectors (Pressure cleaner)