1. Technician A says that a 3 × 5 card should be held against the oil fill opening if the positive crankcase ventilation (PCV) system is operating correctly. Technician B says that if a PCV valve rattles, it's working properly. Who is correct?
A. Neither Technician A nor B
B. Technician A
C. Both Technicians A and B
D. Technician B
2. Which of the following exhaust gases are least likely to be measured in percentages?
A. CO (carbon monoxide)
B. HC (hydrocarbon)
C. CO2 (carbon dioxide)
D. O2 (oxygen)
3. Oxides of nitrogen result from a combination of nitrogen and
A. hydrogen.
B. argon.
C. oxygen.
D. carbon.
4. Technician A says that carbon monoxide (CO) and hydrocarbon (HC) levels should increase if the air injection reactor (AIR) hoses are pinched off. Technician B says that a defective drive belt may cause AIR system problems. Who is correct?
A. Technician A
B. Both Technicians A and B
C. Neither Technician A nor B
D. Technician B
5. Technician A says that the most efficient method of EVAP system leak detection is introducing smoke under low pressure from a machine specifically designed for this purpose. Technician B says that nitrogen gas pressurization uses nitrogen gas under a very low pressure (lower than 1 psi) in the fuel system; you listen for escaping air with amplified headphones. Who is correct?
A. Both Technicians A and B
B. Technician B
C. Neither Technician A nor B
D. Technician A
6. To avoid excessive catalyst temperatures and the possibility of fuel vapors reaching the converter, the following rules are being discussed: Technician A says that it's okay to use any fuel additives or cleaners in the fuel system. Technician B says that you should repair engine problems such as dieseling, misfiring, or stumbling as soon as possible. Who is correct?
A. Technician A
B. Both Technicians A and B
C. Technician B
D. Neither Technician A nor B
7. A scan tool check of the canister purge valve control solenoid shows that it's always open. Which of the following could be the cause?
A. Defective powertrain control module (PCM)
B. Vacuum source problem
C. Broken diaphragm
D. Vacuum passage restriction
8. Two technicians are explaining what exhaust gas emissions tell you about engine operation. Technician A says that the higher the level of CO2 in the exhaust stream, the more efficiently the engine is operating. Technician B says that CO2 levels of 20 to 25 percent are considered acceptable.
A. Technician B
B. Neither Technician A nor B
C. Both Technicians A and B
D. Technician A
9. A maximum reading of _______ parts per million (PPM) of NOx under loaded driving conditions generally means that the vehicle will pass an enhanced I/M roller test.
A. 2,000
B. 100
C. 1,000
D. 500
10. The _______ valve protects the air pump from reverse-exhaust pressure.
A. gulp
B. diverter
C. positive crankcase ventilation (PCV)
D. check
11. The OBD-II catalytic converter monitor uses _______ sensor(s) to monitor catalytic converter efficiency.
A. an engine coolant temperature
B. front and rear catalyst temperature
C. front and rear O2
D. a throttle position
12. Which of these items is least likely to cause an exhaust emissions test failure as a result of excessive NOx emissions?
A. Poor flow through the EGR system
B. Spark plug hot range
C. Defective fuel injector
D. Defective oxygen sensor
13. You're using a scan tool to evaluate the overall exhaust gas recirculation (EGR) system operation on a vacuum-type EGR system. Which one of the following is the best parameter to monitor with a scan tool?
A. EGR temperature sensor voltage during cruise
B. EGR valve operation during deceleration
C. EGR valve operation during acceleration
D. EGR temperature sensor voltage at idle
14. A technician suspects that the exhaust gas recirculation (EGR) valve is closed. Which of the following would indicate a closed EGR valve?
A. Stalling
B. Engine surge
C. Rough idle
D. Spark knock
15. Which of these evaporative control valve(s) is/are normally open?
A. Both the canister purge and canister vent valve
B. Neither the canister purge nor canister vent valve
C. Canister purge valve
D. Canister vent valve
16. Which of these items will least likely increase pressure in the evaporative emission control system?
A. Inlet fuel to the fuel pump
B. Fuel temperature
C. Returned fuel from the fuel-injection system
D. Volatility of the fuel
17. While servicing a vehicle, you retrieve the diagnostic code P0401, "EGR (exhaust gas recirculation) flow insufficient." Which of these is the most likely cause?
A. Stuck-open EGR valve
B. Electrical wiring shorted to voltage
C. Clogged EGR ports or passages
D. Electrical wiring shorted to ground
18. As the efficiency of the catalytic converter drops through deterioration, the switching rate of the rear O2 sensor signal will start to look like the front O2 sensor signal. When the rear O2 sensor signal reaches approximately 75 percent of the front O2 sensor, which of the following is the result?
A. The catalyst beads in the converter should be changed.
B. The diagnostic trouble code is stored with the MIL on.
C. A one-trip flag is set with a code stored, but the MIL isn't activated.
D. The catalytic converter should be replaced.
19. Oxygen combines with nitrogen in the air to form NOx at about _______ °F.
A. 1500
B. 50
C. 000
D. 2500
20. What term describes a catalytic converter as it reaches its effective temperature?
A. Consumption
B. Light-off
C. Firing
D. Initiation
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