High CO at High RPM

This condition indicates abnormally high Carbon Monoxide with low or normal Hydrocarbons during cruise (2500 rpm).

POSSIBLE CAUSE ACTION

Faulty canister purge system Check Evaporative System in
"Testing Procedures" in Emissions



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



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



Verify vehicle remains in Refer to
Closed Loop at steady throttle "Computerized Engine Controls" for
(2500 rpm) and oxygen sensor Self-Diagnostic procedures
is working



Fuel metering malfunction

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