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 System. Refer to TESTING PROCEDURES.



PCV malfunction Check PCV system. Refer to TESTING PROCEDURES.



EGR malfunction Check EGR system. Refer to TESTING PROCEDURES.




Restricted exhaust Check Catalytic Converter. Refer to TESTING PROCEDURES.



Incorrect Spark Advance Check Spark Controls. Refer to COMPUTERS AND CONTROL SYSTEMS.



Verify vehicle remains in Refer to COMPUTERS AND CONTROL SYSTEMS.
Closed Loop at steady throttle
(2500 rpm) and oxygen sensor
is working



Fuel metering malfunction Refer to FUEL SUPPLY AND AIR INDUCTION SYSTEMS and COMPUTERS AND CONTROL SYSTEMS.