Question 1

Explain why a small PCV valve opening is adequate at idle speed.

Accepted Answer

Because the engine is not under heavy load, the amount of blowby gas is minimal and 
the small valve opening is all that is needed.

Question 2

Technician A says high engine temperatures reduce HC and CO emissions. Technician B says incorrect ignition timing can increase the production of NO X .Who is correct?

Accepted Answer

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

Question 3

The PCV system prevents ____________________ gases from escaping to the atmosphere.

Accepted Answer

blowby,crankcase

Question 4

Which of the following is NOT part of an enhanced (OBD-II)evaporative control system?

Accepted Answer

A)  thermal vacuum valve (TVV) 
B)  canister vent solenoid valve
C)  fuel tank vacuum or pressure sensor
D)  canister purge solenoid valve

Question 5

The two factors that have the greatest effect on vehicle emissions are air/fuel ratio and ___________________ at different spots within the combustion chamber.

Accepted Answer

The answer of The two factors that have the greatest...

Question 6

Technician A says oil in the PCV filter and air cleaner can occur if the PCV valve is restricted or plugged. Technician B says oil buildup inside the throttle body can be an indication of high crankcase pressure. Who is correct?

Accepted Answer

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

Question 7

Technician A says a three-way catalytic converter (TWC)oxidizes carbon monoxide and hydrocarbons into carbon dioxide and water. Technician B says a TWC reduces NO x into nitrogen and carbon dioxide. Who is correct?

Accepted Answer

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

Question 8

EGR flow is disabled during throttle openings greater than ___________________ percent

Accepted Answer

The answer of EGR flow is disabled during throttle openings...

Question 9

A digital EGR valve contains up to three electric solenoids that are operated directly by the PCM.

Accepted Answer

A) True 
 B)False

Question 10

How is acid rain related to automotive emissions?

Accepted Answer

The answer of How is acid rain related to automotive...

Question 11

The first controlled automotive emission was ______.

Accepted Answer

A)  crankcase vapors
B)  tailpipe emissions (HC and CO) 
C)  NO X
D)  evaporative emissions

Question 12

OBD-II systems monitor the EVAP system for leaks.

Accepted Answer

A) True 
 B)False

Question 13

Most current light-duty diesel engines use a ___________________ rail injection system.

Accepted Answer

The answer of Most current light-duty diesel engines use a...

Question 14

An I/M 240 test lasts _____ minutes.

Accepted Answer

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

Question 15

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 16

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 17

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

Accepted Answer

A) True 
 B)False

Question 18

NO _X , HC, and CO are changed into harmless gases by the ____________________ in the three way catalytic converter.

Accepted Answer

The answer of NO _X , HC, and CO are...

Question 19

Where does a secondary air injection system deliver its air supply when the engine is cold and at operating temperature?

Accepted Answer

The answer of Where does a secondary air injection system...

Question 20

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

Accepted Answer

A) True 
 B)False

Exam 33: Emission Control Systems

Explain why a small PCV valve opening is adequate at idle speed.

Technician A says high engine temperatures reduce HC and CO emissions. Technician B says incorrect ignition timing can increase the production of NO _X .Who is correct?

The PCV system prevents ____________________ gases from escaping to the atmosphere.

Which of the following is NOT part of an enhanced (OBD-II) evaporative control system?

The two factors that have the greatest effect on vehicle emissions are air/fuel ratio and ___________________ at different spots within the combustion chamber.

Technician A says oil in the PCV filter and air cleaner can occur if the PCV valve is restricted or plugged. Technician B says oil buildup inside the throttle body can be an indication of high crankcase pressure. Who is correct?

Technician A says a three-way catalytic converter (TWC) oxidizes carbon monoxide and hydrocarbons into carbon dioxide and water. Technician B says a TWC reduces NO _x into nitrogen and carbon dioxide. Who is correct?

EGR flow is disabled during throttle openings greater than ___________________ percent

A digital EGR valve contains up to three electric solenoids that are operated directly by the PCM.

How is acid rain related to automotive emissions?

The first controlled automotive emission was ______.

OBD-II systems monitor the EVAP system for leaks.

Most current light-duty diesel engines use a ___________________ rail injection system.

An I/M 240 test lasts _____ minutes.

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 ____________________.

Under what conditions is the EGR valve open?

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

NO _X , HC, and CO are changed into harmless gases by the ____________________ in the three way catalytic converter.

Where does a secondary air injection system deliver its air supply when the engine is cold and at operating temperature?

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

Exam 33: Emission Control Systems

Explain why a small PCV valve opening is adequate at idle speed.

Technician A says high engine temperatures reduce HC and CO emissions. Technician B says incorrect ignition timing can increase the production of NO X .Who is correct?

The PCV system prevents ____________________ gases from escaping to the atmosphere.

Which of the following is NOT part of an enhanced (OBD-II) evaporative control system?

The two factors that have the greatest effect on vehicle emissions are air/fuel ratio and ___________________ at different spots within the combustion chamber.

Technician A says oil in the PCV filter and air cleaner can occur if the PCV valve is restricted or plugged. Technician B says oil buildup inside the throttle body can be an indication of high crankcase pressure. Who is correct?

Technician A says a three-way catalytic converter (TWC) oxidizes carbon monoxide and hydrocarbons into carbon dioxide and water. Technician B says a TWC reduces NO x into nitrogen and carbon dioxide. Who is correct?

EGR flow is disabled during throttle openings greater than ___________________ percent

A digital EGR valve contains up to three electric solenoids that are operated directly by the PCM.

How is acid rain related to automotive emissions?

The first controlled automotive emission was ______.

OBD-II systems monitor the EVAP system for leaks.

Most current light-duty diesel engines use a ___________________ rail injection system.

An I/M 240 test lasts _____ minutes.

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 ____________________.

Under what conditions is the EGR valve open?

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

NO X , HC, and CO are changed into harmless gases by the ____________________ in the three way catalytic converter.

Where does a secondary air injection system deliver its air supply when the engine is cold and at operating temperature?

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

Technician A says high engine temperatures reduce HC and CO emissions. Technician B says incorrect ignition timing can increase the production of NO _X .Who is correct?

Technician A says a three-way catalytic converter (TWC) oxidizes carbon monoxide and hydrocarbons into carbon dioxide and water. Technician B says a TWC reduces NO _x into nitrogen and carbon dioxide. Who is correct?

NO _X , HC, and CO are changed into harmless gases by the ____________________ in the three way catalytic converter.