High CO - at High RPM

This condition, abnormally high Carbon Monoxide with low or normal Hydrocarbons during cruise (2500 rpm), may indicate a problem in one or more of the areas listed below.

POSSIBLE CAUSE ACTION

Faulty canister purge system To check EVP system proceed to
EVAPORATIVE EMISSION CONTROL SYSTEM

PCV malfunction To check PCV system proceed to
POSITIVE CRANKCASE VENTILATION SYSTEM.


EGR malfunction To check EGR system proceed to
EXHAUST GAS RECIRCULATION SYSTEM.


Restricted exhaust To check TWC proceed to
CATALYTIC CONVERTER.


Incorrect Spark Advance Refer to
COMPUTERIZED ENGINE CONTROLS.


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