High CO - at High RPM

This condition is indicated by abnormally high carbon monoxide with low or normal hydrocarbon emissions during cruise (2500 rpm).


POSSIBLE CAUSE ACTION


Faulty canister purge system Check Evaporative Control System


PCV malfunction Check PCV system


EGR malfunction Check EGR system


Restricted exhaust Check Catalytic Converter



Incorrect Spark Advance Check electronic spark controls



Verify vehicle is operating in Refer to ON-BOARD
Closed Loop at steady throttle DIAGNOSTICS
(2500rpm) and oxygen sensor
is working



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