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



PCV malfunction Check PCV system in "Testing
Procedures"





Restricted exhaust Check Catalytic Converter in
"Testing Procedures"



Incorrect Spark Advance Check Ignition Timing in "Adjustment
Procedures"




Verify vehicle remains in Test the Fuel Injection System
Closed Loop at steady throttle Refer to "On-Board Diagnostics" for models so equipped
(2500 rpm) and oxygen sensor
is working





Fuel Injected Check fuel pressure
Fuel Metering Malfunction Perform injector balance test
Service Fuel Injectors (Pressure cleaner)