Question 1

Detonation sensors are being discussed. Technician A says most detonation sensors produce an analog signal. Technician B says the detonation sensor may be mounted in the exhaust. Who is correct?

Accepted Answer

A)   A only
B)   B only
C)   both A and B
D)   neither A nor B A

Question 2

Technician A says the production of CO2 is directly related to the amount of fuel consumed; therefore, more fuel-efficient engines produce less CO2. Technician B says imposing new CAFE [fuel economy] standards will, in effect, reduce CO2 emissions. Who is correct?

Accepted Answer

A)   A only
B)   B only
C)   both A and B
D)   neither A nor B C

Question 3

A digital EGR valve has up to _____ solenoids.

Accepted Answer

A)   three
B)   four
C)   six
D)   eight A

Question 4

The normal operating temperature for most catalytic converters is about ______.

Accepted Answer

A)   450°F (235°
C)  
B)   900°F (500°
C)  
C)   1,200°F (650°
C)  
D)   1,400°F (750°
C)

Question 5

Technician A says the EVAP monitor for an OBD-II system determines whether there is sufficient purge flow by varying the purge solenoid duty cycle while monitoring change in STFT. Technician B says the canister vent solenoid must be open during the EVAP pressure test portion of the monitor. Who is correct?

Accepted Answer

A)   A only
B)   B only
C)   both A and B
D)   neither A nor B

Question 6

Heated air inlet systems, manifold heat control valves [heat risers], and EFE heater grids were used on older cars with carburetors and TBI fuel injection to prevent vaporized fuel from condensing inside the ____________________.

Accepted Answer

The answer of Heated air inlet systems, manifold heat control...

Question 7

NOX emissions are caused by nitrogen and oxygen uniting at cylinder temperatures above ______.

Accepted Answer

A)   250°F (121°
C)  
B)   500°F (260°
C)  
C)   2,500°F (1,371°
C)  
D)   5,000°F (2,760°
C)

Question 8

Excessive oxygen in the exhaust indicates an improper air/fuel mixture.

Accepted Answer

A) True 
 B)False

Question 9

Technician A says the EGR vent solenoid is normally open. Technician B says the EGR control solenoid is normally open. Who is correct?

Accepted Answer

A)   A only
B)   B only
C)   both A and B
D)   neither A nor B

Question 10

OBD-II systems monitor the EVAP system for leaks.

Accepted Answer

A) True 
 B)False

Question 11

Carbon monoxide is being discussed. Technician A says as the air/fuel ratio becomes richer, the CO levels decrease. Technician B says CO is a colorless, odorless, and highly poisonous gas that can cause death. Who is correct?

Accepted Answer

A)   A only
B)   B only
C)   both A and B
D)   neither A nor B

Question 12

A ____________________type EGR valve has three electric solenoids. Each of the solenoids and orifices has a different size. The rate of flow is based on the combination of solenoids turned on by the PCM.

Accepted Answer

The answer of A ____________________type EGR valve has three electric...

Question 13

An ignition misfire can cause excessive carbon monoxide emissions in the exhaust.

Accepted Answer

A) True 
 B)False

Question 14

What is the function of glow plugs?

Accepted Answer

The answer of What is the function of glow plugs?...

Question 15

Under what conditions is the EGR valve open?

Accepted Answer

A)   starting
B)   idle [warm engine]
C)   cruise [warm engine]
D)   Wide open throttle

Question 16

Describe the purpose of the EVAP system.

Accepted Answer

The answer of Describe the purpose of the EVAP system....

Question 17

Blowby gases condense in the crankcase and react with the oil to form ______.

Accepted Answer

A)   carbon black
B)   varnish
C)   hydrocarbons
D)   sludge

Question 18

Three types of emissions being controlled in gasoline engines are ____________________, ____________________, and ____________________.

Accepted Answer

The answer of Three types of emissions being controlled in...

Question 19

A three-way catalytic converter [TWC] stores oxygen when the air/fuel ratio is rich.

Accepted Answer

A) True 
 B)False

Question 20

The ____________________ system removes blowby gases from the crankcase and recirculates them to the engine intake.

Accepted Answer

The answer of The ____________________ system removes blowby gases from...

Exam 33: Emission Control Systems

Detonation sensors are being discussed. Technician A says most detonation sensors produce an analog signal. Technician B says the detonation sensor may be mounted in the exhaust. Who is correct?

Technician A says the production of CO₂ is directly related to the amount of fuel consumed; therefore, more fuel-efficient engines produce less CO₂. Technician B says imposing new CAFE [fuel economy] standards will, in effect, reduce CO₂ emissions. Who is correct?

A digital EGR valve has up to _____ solenoids.

The normal operating temperature for most catalytic converters is about ______.

Heated air inlet systems, manifold heat control valves [heat risers], and EFE heater grids were used on older cars with carburetors and TBI fuel injection to prevent vaporized fuel from condensing inside the ____________________.

NO_X emissions are caused by nitrogen and oxygen uniting at cylinder temperatures above ______.

Excessive oxygen in the exhaust indicates an improper air/fuel mixture.

Technician A says the EGR vent solenoid is normally open. Technician B says the EGR control solenoid is normally open. Who is correct?

OBD-II systems monitor the EVAP system for leaks.

Carbon monoxide is being discussed. Technician A says as the air/fuel ratio becomes richer, the CO levels decrease. Technician B says CO is a colorless, odorless, and highly poisonous gas that can cause death. Who is correct?

A ____________________type EGR valve has three electric solenoids. Each of the solenoids and orifices has a different size. The rate of flow is based on the combination of solenoids turned on by the PCM.

An ignition misfire can cause excessive carbon monoxide emissions in the exhaust.

What is the function of glow plugs?

Under what conditions is the EGR valve open?

Describe the purpose of the EVAP system.

Blowby gases condense in the crankcase and react with the oil to form ______.

Three types of emissions being controlled in gasoline engines are , , and .

A three-way catalytic converter [TWC] stores oxygen when the air/fuel ratio is rich.

The ____________________ system removes blowby gases from the crankcase and recirculates them to the engine intake.