High CO and HC -- at Idle

This condition, at idle, is indicated by abnormally high carbon monoxide AND hydrocarbon emissions.

POSSIBLE CAUSE
VERY RICH Air-Fuel mixture.

ACTION
Check Air/Fuel ratio.
Perform injector balance test
Inspect regulator operation (check vacuum line and return hose).
Check fuel pressure.



POSSIBLE CAUSE
Malfunctioning air pump.

ACTION
Check Air Injection system.



POSSIBLE CAUSE
Faulty Fuel Evaporative system.

ACTION
Check Fuel Evaporative system vapor lines, purge solenoid and valves.



POSSIBLE CAUSE
Fuel in crankcase being sucked through PCV valve.

ACTION
Remove PCV valve from crankcase and retest emissions.



POSSIBLE CAUSE
Engine misfire with Closed Loop fuel metering, causing system to go full rich.

ACTION
Check fuel feedback (Oxygen sensor).
For rich trouble code, see "Computers and Control Systems".