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

PCV malfunction Check PCV system in TESTING
PROCEDURES

EGR malfunction Check EGR system in TESTING
PROCEDURES

Restricted exhaust Check Catalytic Converter in
TESTING PROCEDURES

Incorrect Spark Advance Check Spark Controls in
COMPUTERIZED ENGINE CONTROLS

Verify vehicle remains in Refer to COMPUTERIZED ENGINE
Closed Loop at steady throttle CONTROLS for
(2500 rpm) and oxygen sensor Self-Diagnostic procedures
is working

Fuel metering malfunction Check fuel pressure
Inspect regulator operation
(check vacuum line and return hose),
Service Fuel Injector (Pressure cleaner)