Deck 13: Emission Controls

Question 1

What is the purpose of the DEF heating circuit?

A) To heat the DEF to dosing temperatures.
B) To prevent DEF freezing in colder climates.
C) To create steam pressure in the DEF canister.
D) To convert liquid DEF to a gas state.

Answer 1

B

Question 2

In 2004, what system became a requirement on highway compliant diesel engines to meet tough emissions standards?

A) Diesel particulate filters (DPFs).
B) Selective catalytic reduction (SCRs).
C) Positive crankcase ventilation (PCV).
D) Exhaust gas recirculation (EGR).

Answer 2

D

Question 3

What piston design feature aids in reducing HC emissions?

A) Mexican hat crowns.
B) High-headland volume.
C) Offset piston crown designs.
D) Low-headland volume.

Answer 3

D

Question 4

The diesel exhaust fluid reservoir cap is always what color?

A) Red.
B) Black.
C) Green.
D) Blue.

Question 5

What is the ideal or preferred DPF regeneration cycle?

A) Active.
B) Manual.
C) Passive.
D) Low temperature.

Question 6

What is the biggest single source of carbon monoxide emissions in North America?

A) Industry emissions.
B) Gasoline and diesel engines.
C) Off highway light cuty diesel engines.
D) Heavy duty diesel engines.

Question 7

Positive crankcase ventilation (PCV) may also be known by what term on diesel engines?

A) Forced crankcase ventilation (FCV).
B) Sealed crankcase ventilation (SCV).
C) Crankcase venting.
D) Closed crankcase ventilation (CCV).

Question 8

What are typical operating temperatures in a DPF?

A) Exceeding 1,100degF (600degC).
B) Less than 400 degF (200degC).
C) Approaching 11,000 degF (600 degC).
D) DPFs operate at ambient temperatures.

Question 9

What type of sensor is often used to by the PCM to determine SCR effectiveness?

A) Dosing sensor.
B) Oxide sensor.
C) Oxygen sensor.
D) SCR outlet temperature sensor.

Question 10

Hydrocarbons emitted in a gaseous state are referred to as?

A) Carbon monoxide.
B) Carbon dioxide.
C) Volatile organic compounds (VOCs).
D) Sulfur dioxide.

Question 11

What is the primary cause of harmful tailpipe emissions?

A) Low quality fuel.
B) Low ignition temperatures.
C) Nitrogen enriched fuel.
D) Imperfect combustion.

Question 12

What tailpipe emission can only be reduced by increasing fuel efficiency?

A) Carbon dioxide.
B) Particulate matter (PM).
C) Ozone.
D) Nitrogen dioxide.

Question 13

What do all post-2007 diesel particulate filters (DPFs) require periodically?

A) Filter replacement.
B) Bench testing to meet EPA standards.
C) Service intervention to remove ash residues.
D) Pressure testing to check for leaks.

Question 14

Technican A states that EPA emission standards for model year must be adhered to by manufacturers. Technician B states that CARB emission standards apply to more states than just California. Who is correct?

A) Technician A only.
B) Technician B only.
C) Both A and B.
D) Neither A nor B.

Question 15

What system can be said to provide the most effective means for controlling emissions?

A) Engine management computer.
B) Fuel injection systems.
C) Ignition timing systems.
D) Cooling and lubrication.

Question 16

Technician A states that a rust damaged catalytic converter should be replaced. Technician B suggests repairing a rust damaged catalytic converter with metal patches. Who is correct?

A) Technician A only.
B) Technician B only.
C) Both A and B.
D) Neither A nor B.

Question 17

What is the function of the selective catalytic reduction system?

A) Reduce oxides of nitrogen to oxygen and nitrogen.
B) Reduce ozone to atmospheric oxygen.
C) Reduce carbon monoxides to carbon dioxide.
D) Reduce particulate matter into ash.

Question 18

What are the two stages of a NOx Adsorber catalyst?

A) Detection and reduction.
B) Heating and cooling.
C) Reduction and regeneration.
D) Storage and reduction.

Question 19

What metal is typically used as a reduction catalyst in reduction stage converters?

A) Stainless steel.
B) Rhodium.
C) Palladium.
D) Platinum.

Question 20

What type of smog is produced by the reaction of tailpipe gases and sunlight?

A) Sulfur dioxide.
B) Carbon Monoxide.
C) Volatile organic compounds (VOCs).
D) Photochemical.