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


Fuel Injected 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 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 with Closed Loop Check fuel injection
fuel metering, causing system
to go full rich