Excessive HC Emissions-Air/Fuel Mixtures Not Completely Burned

1. Engine not at normal operating temperature.
2. Disconnected, blocked, leaking, or improperly routed vacuum hoses.
3. Vacuum leaks.
4. Improper idle mixture.
5. Sticking or improperly adjusted choke.
6. Incorrect spark timing.
7. Faulty spark plugs, wires, or distributor cap.
8. Improperly operating pulse air or secondary air control system.
9. Lead contamination of catalytic converter.
a. Check for absence of fuel tank filler neck restricter.
10. Faulty feedback system.