High CO, Low or Normal HC at Idle

DEFINITION
At idle indicates abnormally high Carbon Monoxide while the Hydrocarbons remain normal or low.

POSSIBLE CAUSE ACTION

Rich Air-Fuel mixture Check - Air/Fuel ratio
- Regulator operation
(check vacuum line and return hose)
- Fuel pressure refer to FUEL SYSTEM PRESSURE
TEST/ DIAGNOSIS, TESTING AND INSPECTION
PROCEDURES in FUEL SUPPLY AND AIR INDUCTION



Dirty air filter Clean/replace As required
.


Saturated EVAP canister or Check EVAP system.
malfunctioning vapor purge system