High HC & CO - at High RPM

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

POSSIBLE CAUSE ACTION


Electrical misfires Check ignition system



Vacuum leak Check vacuum lines and routing in
"Vacuum and Vapor Hose Routing"
in Emissions - Check intake manifold
and vacuum components



PCV malfunction Check PCV system in "Testing
Procedures" in Emissions



EGR malfunction Check EGR system in "Testing
Procedures" in Emissions



Restricted exhaust Check Catalytic Converter in
"Testing Procedures" in Emissions



Initial timing incorrect Check Ignition Timing in "Adjustment
Procedures" in Emissions




Fuel metering malfunction

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