High HC - at High RPM
This condition indicates abnormally high Hydrocarbons with low or normal CO during cruise (2500 RPM).
POSSIBLE CAUSE ACTION
Electrical misfires ^ Check ignition system
Vacuum leak ^ Check vacuum lines and routing. SEE Diagrams
^ Check intake manifold and vacuum components
[1][2]PCV malfunction ^ Check PCV system.
Initial timing incorrect ^ Check Distributor Assembly installation.
Incorrect Spark Advance ^ Check Spark Controls.
EGR malfunction ^ Check EGR system. Exhaust Gas Recirculation