High CO, Low or Normal HC at Idle

This condition, at idle, indicates an abnormally high Carbon Monoxide level while the Hydrocarbon content remains normal or low.

POSSIBLE CAUSE ACTION

Fuel Injected Check Air/Fuel ratio. Inspect regulator operation. Check vacuum line and return hose. Check fuel pressure.



Dirty air filters Clean or Replace.



Saturated fuel evaporative canister Check the Fuel Evaporative system
or malfunctioning vapor purge system under TESTING PROCEDURES.



Malfunctioning Closed Loop fuel metering Refer to
system - Exhaust leak or other false COMPUTERIZED ENGINE CONTROLS
indications "fooling" oxygen sensor to for testing of the computerized
sense a lean condition feedback system.




Stuck or restricted [1][2]PCV Check the PCV system under TESTING
valve and/or hose PROCEDURES.