High HC & CO - at High RPM

Condition: High Carbon Monoxide and Hydrocarbons during cruise (2500 rpm).


POSSIBLE CAUSE ACTION


Electrical misfires Check ignition system.
SEE Powertrain Management/Ignition System/Testing and Inspection/Oscilloscope Patterns and Waveforms.

Initial timing incorrect Check base timing.
SEE Ignition System/ ADJUSTMENT PROCEDURES.

Incorrect Spark Advance Check Spark Controls.
SEE Ignition System/ TIMING SPECIFICATIONS

Vacuum leak Check vacuum lines and routing.
Refer to Vehicle Emission Control Information (VECI) label under hood.

Check intake manifold
and vacuum components

Faulty canister purge system Check Fuel Evaporative System.

Restricted exhaust Check Catalytic Converter.

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


Fuel Injection malfunction Check fuel pressure.
Perform injector balance test.
Service Fuel Injectors (Pressure cleaner).