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 in
"Vacuum and Vapor Hose Routing"
in Emissions - Check intake manifold
and vacuum components



PCV malfunction Check PCV system in "Testing
Procedures" in Emissions



EGR malfunction Check EGR system in "Testing
Procedures" in Emissions



Initial timing incorrect Check Ignition Timing in "Adjustment
Procedures" in Emissions