Chapter 15 Fuel and Emission Control Systems 325 Copyright by Goodheart-Willcox Co., Inc. 3. Technician A says that a throttle body assembly for a multiport injection system is used to control airflow into the engine. Technician B says that a throttle body assembly for a throttle body injection system is used to control fuel flow into the engine. Who is correct? (A) A only. (B) B only. (C) Both A and B. (D) Neither A nor B. 4. All of the following are typical sensors used in a fuel injection system except: (A) knock sensor. (B) mass airflow sensor. (C) engine coolant temperature sensor. (D) oxygen sensor. 5. Technician A says that a throttle body for a throttle body injection system normally contains the system’s fuel pressure regulator. Technician B says that the throttle body for a throttle body injection system normally contains the fuel injector(s). Who is correct? (A) A only. (B) B only. (C) Both A and B. (D) Neither A nor B. 6. Technician A says that to clear the trouble codes from most computer systems, you should disconnect the ECM from battery power. Technician B says that to clear the trouble codes from an OBD II computer system, you must use a scan tool. Who is correct? (A) A only. (B) B only. (C) Both A and B. (D) Neither A nor B. 7. Technician A says that hydrocarbon emission can be caused by incomplete burning of the fuel in the engine’s combustion chambers. Technician B says that hydrocarbon emission can be caused by fuel evaporation. Who is correct? (A) A only. (B) B only. (C) Both A and B. (D) Neither A nor B. 8. Technician A says that wider spark plug gaps are used on today’s vehicles to burn leaner fuel mixtures. Technician B says that today’s automotive engines are equipped with hotter thermostats to reduce HC and CO emissions. Who is correct? (A) A only. (B) B only. (C) Both A and B. (D) Neither A nor B. 9. Technician A says that an engine’s PCV valve can be located in a valve cover. Technician B says that an engine’s PCV valve can be located in the intake manifold. Who is correct? (A) A only. (B) B only. (C) Both A and B. (D) Neither A nor B. 10. Which type of catalytic converter is most commonly used on modern automotive exhaust systems? (A) Pellet converter. (B) Three-way converter. (C) Four-way converter. (D) All of the above.