High CO and HC at Idle

DEFINITION: At idle indicates abnormally high Carbon Monoxide and Hydrocarbons.

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 Fuel Evaporative system.
vapor lines, purge solenoid
and valves




Fuel in crankcase being Remove [1][2]PCV from crankcase
sucked through PCV valve and retest emissions.