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
[1][2]C Charts



Vacuum leak Check vacuum lines and routing.
See DIAGRAMS
Check intake manifold, and vacuum components.



[1][2]PCV malfunction Check PCV system. Testing and Inspection



EGR malfunction Check EGR system. Testing and Inspection



Incorrect Spark Advance Check Spark Controls (EST, ESC etc..).