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 bowl vent/canister purge system Check Evaporative System


PCV malfunction Check PCV system



EGR malfunction Check EGR system


Restricted exhaust Check Catalytic Converter



Incorrect Spark Advance Check distributor advance mechanism,
vacuum hose, and routing



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 carburetor passages, bleeds
and restrictors, internal leaks,
float level, metering rods and gaskets
Replace or rebuild if faults are found