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. Evaporative Emissions System



PCV malfunction Check PCV system. Positive Crankcase Ventilation



EGR malfunction Check EGR system. Exhaust Gas Recirculation




Restricted exhaust Check Catalytic Converter. Catalytic Converter



Incorrect Spark Advance Check Spark Controls. Refer to COMPUTERS AND CONTROL SYSTEMS. 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 Computers and Control Systems



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