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
Check intake manifold
and vacuum components



[1][2]PCV malfunction Check PCV system


EGR malfunction Check EGR system


Initial timing incorrect Check ignition timing



Incorrect Spark Advance Check spark controls (EST ESC)



Verify vehicle remains in Perform Self-diagnostic procedures
Closed Loop at steady throttle
(2500 rpm) and oxygen sensor
is working