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 ratio,
inspect regulator operation
(check vacuum line and return hose),
check fuel pressure



Faulty Fuel Evaporative system, Check Fuel Evaporative system
vapor lines, purge solenoid in TESTING PROCEDURES
and valves



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



Engine misfire with Closed Loop Refer to COMPUTERIZED ENGINE
fuel metering, causing system CONTROLS
to go full rich for rich trouble code,
check fuel feedback (Oxygen sensor)