High HC & CO - at High RPM

This condition indicates abnormally high Carbon Monoxide and Hydrocarbons during cruise (2500 rpm).

POSSIBLE CAUSE ACTION


Electrical misfires Refer to Ignition Systems,
Testing and Inspection



Vacuum leak Check vacuum lines and routing
Check intake manifold and vacuum components



PCV malfunction Positive Crankcase Ventilation



Restricted exhaust Refer to Catalytic Converter, Testing and Inspection


Initial timing incorrect Check the On-Board Diagnostic System for fault codes Refer to Computers and Control Systems, Testing and Inspection




Fuel metering malfunction Check fuel pressure
Perform injector balance test
Inspect regulator operation
(check vacuum line and return hose),
Service Fuel Injectors (Pressure cleaner)
Refer to Fuel Delivery and Air Induction, Testing and Inspection