High CO - at High RPM

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

POSSIBLE CAUSE ACTION


Faulty canister purge system ^ Check Fuel Evaporative System.


Restricted exhaust ^ Check Catalytic Converter.


EGR malfunction ^ Check EGR system.


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).