High CO and HC - at Idle

This condition, at idle, indicates abnormally high Carbon Monoxide and Hydrocarbons.

POSSIBLE CAUSE ACTION


VERY RICH Air-Fuel mixture Check Air/Fuel Mixture
Perform injector balance test, Inspect regulator operation (check vacuum line and return hose),
Check fuel pressure,
Refer to Fuel Delivery and Air Induction,Testing and Inspection

Check the On-Board Diagnostic system
for fault codes,
Refer to Computers and Control Systems, Testing and Inspection



Faulty Fuel Evaporative system,
vapor lines, purge solenoid
or valves Evaporative Emissions System



Fuel in crankcase being
sucked through PCV valve Remove PCV lines from crankcase
and retest emissions