High CO - at High RPM

Symptom: High Carbon Monoxide, normal or low Hydrocarbons during cruise (2500 rpm).

POSSIBLE CAUSE ACTION


Verify vehicle remains in Closed ^ SEE COMPUTERS AND CONTROL SYSTEMS/
Loop. OXYGEN SENSOR TESTING.



Faulty EVAP Canister purge system ^ Check Fuel Evaporative System.
Evaporative Emissions System


Restricted exhaust ^ Check Catalytic Converter.



EGR malfunction ^ Check EGR system.
Exhaust Gas Recirculation


[1][2]PCV malfunction ^ Check PCV system.


Initial timing incorrect ^ Check base timing.
SEE IGNITION SYSTEM/ ADJUSTMENT PROCEDURES.

^ Check Timing belt alignment.


Incorrect Spark Advance ^ Check Spark Controls.
SEE IGNITION SYSTEM/ TIMING SPECIFICATIONS


Fuel Injection malfunction ^ Check fuel pressure.

^ Perform injector balance test.

^ Service Fuel Injectors (Pressure cleaner).