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



Faulty Fuel Evaporative system, Check EVAP system. Refer to TESTING PROCEDURES.
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 COMPUTERS AND CONTROL SYSTEMS.
fuel metering, causing system
to go full rich