High CO at High RPM

DEFINITION
Abnormally high Carbon Monoxide with low or normal Hydrocarbons during cruise (2500 rpm)


POSSIBLE CAUSE ACTION

Canister purge system Check EVAP System.



[1][2]PCV malfunction Check PCV system.



EGR malfunction Check EGR system.



Restricted exhaust Check - Catalytic converter.
- Exhaust system for collapsed/
pinched pipes and muffler damage



Incorrect Spark Advance Check Spark controls (EST ESC)



Vehicle remains in Perform O2 sensor test
Open Loop at steady throttle refer to OXYGEN SENSOR TESTING/
(2500 rpm) DIAGNOSIS, TESTING AND INSPECTION PROCEDURES
in COMPUTERS AND CONTROL SYSTEMS



Fuel Injection system Check - Fuel pressure
refer to FUEL SYSTEM PRESSURE
TEST/ DIAGNOSIS, TESTING AND INSPECTION
PROCEDURES in FUEL SUPPLY AND AIR INDUCTION
- Regulator operation
(check vacuum line and return hose)
- Service Fuel Injector (Pressure cleaner)