High HC - at High RPM

CONDITION
High Hydrocarbons, normal or low Carbon Monoxide during cruise (2500 RPM).

POSSIBLE CAUSE ACTION


Electrical misfires ^ Check ignition system.



Vacuum leak ^ Check vacuum lines and routing.

^ SEE Vehicle Emission Control Information (VECI) label under hood.

^ Check intake manifold and vacuum components.


CCV malfunction ^ Check CCV system.


Incorrect Spark Advance ^ Check Spark Controls.