Please help me with the following questions - Automechanics

1.   Which one of the following is a prime source of problems in secondary air systems?
    
A. Engine coolant
B. Engine oil
C. Water
D. Dirt

2.   The positive crankcase ventilation (PCV) system helps reduce _______ exhaust gas emissions.
    
A. NOx (oxides of nitrogen)
B. oxygen
C. HC (hydrocarbon)
D. CO2 (carbon dioxide)

3.   Which of these engine concerns may be caused by a stuck-open exhaust gas recirculation (EGR) valve?
    
A. Excessive NOx exhaust emissions
B. Engine missing at highway speed
C. Ping (spark knock or detonation)
D. Rough idle/stalling

4.   The _______ valve protects the air pump from reverse-exhaust pressure.
    
A. check
B. diverter
C. gulp
D. positive crankcase ventilation (PCV)

5.   Which of these items will least likely increase pressure in the evaporative emission control system?
    
A. Volatility of the fuel
B. Returned fuel from the fuel-injection system
C. Fuel temperature
D. Inlet fuel to the fuel pump

7.   A technician suspects that the exhaust gas recirculation (EGR) valve is closed. Which of the following would indicate a closed EGR valve?
    
A. Rough idle
B. Stalling
C. Spark knock
D. Engine surge
 

8.   Which of these evaporative control valve(s) is/are normally open?
    
A. Canister vent valve
B. Canister purge valve
C. Neither the canister purge nor canister vent valve
D. Both the canister purge and canister vent valve