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, flooding or
leaking carburetor, partially
closed choke, high fuel level (float),
and dirty air bleeds




Malfunctioning AIR system Check Air Injection system


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



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



Engine misfire with Closed Loop Refer to rich trouble code,
fuel metering, causing system check Oxygen sensor
to go full rich