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 in
"Testing Procedures"



PCV malfunction Check PCV system in "Testing
Procedures"



EGR malfunction Check EGR system in "Testing
Procedures"



Restricted exhaust Check Catalytic Converter in
"Testing Procedures"



Incorrect Spark Advance Check Spark Controls in
"Computerized
Engine Controls"



Verify vehicle remains in Refer to
Closed Loop at steady throttle "Computers And Control Systems" for
(2500 rpm) and oxygen sensor Self-Diagnostic procedures
is working




Fuel metering malfunction


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