High CO and HC - at Idle

This condition, at idle, is indicated by abnormally high carbon monoxide AND hydrocarbon emissions.

POSSIBLE CAUSE ACTION

VERY RICH Air-Fuel mixture Check Air/Fuel ratio,
perform injector balance test,
inspect regulator operation
(check vacuum line and return hose),
check fuel pressure



Malfunctioning air pump Check Air Injection system
in "Testing Procedures" in Emissions



Faulty Fuel Evaporative system, Check Fuel Evaporative system
vapor lines, purge solenoid in "Testing Procedures" in Emissions
and valves



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



Engine misfire during closed loop Refer to "Fuel Injection and
operation, causing system Computers and Control Systems"
to go full rich for rich trouble code,
check fuel feedback (Oxygen sensor)