High CO & HC - at Idle

Condition: High Carbon Monoxide and Hydrocarbons, at idle.

POSSIBLE CAUSE ACTION


Very rich Air-Fuel mixture Check fuel pressure.
Check O2 sensor output voltage.
Perform injector balance test (MPI).

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

Fuel in crankcase being Remove PCV Valve
sucked through PCV Valve from crankcase, (so [1][2]PCV sucks
fresh air), and retest emissions.
Diagnose and repair cause, change oil and retest.


Dirty air filter Clean or replace filter.