High HC and CO -- at High RPM

This condition is indicated by abnormally high carbon monoxide AND hydrocarbon emissions during cruise (2500 rpm).

POSSIBLE CAUSE
Electrical misfires.

ACTION
Check ignition system.



POSSIBLE CAUSE
Vacuum leak.

ACTION
Check vacuum lines and routings.
Check intake manifold and vacuum components.



POSSIBLE CAUSE
Faulty bowl vent/canister purge system.

ACTION
Check Evaporative System. Evaporative Emissions System



POSSIBLE CAUSE
PCV malfunction.

ACTION
Check PCV system. Positive Crankcase Ventilation



POSSIBLE CAUSE
Restricted exhaust.

ACTION
Check Catalytic Converter. Catalytic Converter



POSSIBLE CAUSE
Initial timing incorrect.

ACTION
Check Ignition Timing.



POSSIBLE CAUSE
Incorrect spark advance.

ACTION
Check spark controls.



POSSIBLE CAUSE
Fuel metering malfunction.

ACTION
Check fuel pressure.
Perform injector balance test.
Test regulator operation (check vacuum line and return hose).
Service fuel injectors (pressure clean).