Deck 11: Im Failure Diagnosis and Five-Gas Exhaust Analysis

Question 1

If the emission levels on a 4-gas analyzer indicate that both CO and HC are high and both O₂ and CO₂ are low, what could this indicate?

A) a rich mixture
B) a lean mixture
C) the stoichiometric mixture
D) none of the above

Answer 1

A

Question 2

If the emission levels on a 4-gas analyzer indicate that both O₂ and HC are high and CO₂ and CO are both low, what could this indicate?

A) a rich mixture
B) a lean mixture
C) the stoichiometric mixture
D) none of the above

Answer 2

A

Question 3

The level oxides of nitrogen exhaust emissions are highest when the air/fuel ratio is slightly rich.

Answer 3

False

Question 4

When the vehicle is running rich, oxygen levels are at their highest point.

Question 5

High levels of NO_X emissions may be the result of a lean air/fuel mixture.

Question 6

A vehicle that has failed a state emissions inspection for high CO levels may have a problem with a:

A) fuel-saturated EVAP canister
B) defective EGR valve
C) defective fuel filler cap
D) none of the above

Question 7

CO levels are highest when the vehicle is operating at the stoichiometric ratio.

Question 8

During a tailpipe emissions test, an audible engine "ping" occurs under a load. What emission gas would you anticipate to be elevated to the point of a potential emission failure?

A) HC
B) CO
C) NO_X
D) none of the above

Question 9

The catalytic converter affects the exhaust analyzer reading of:

A) HC
B) CO
C) CO₂
D) both A and B

Question 10

Water may be present in the combustion chamber during the combustion process as a result of:

A) a normal byproduct of combustion
B) contaminated fuel
C) atmospheric humidity
D) all of the above

Question 11

If the emission levels on a 4-gas analyzer indicate that CO₂ is high and HC, O₂ and CO are all low, what could this indicate?

A) a rich mixture
B) a lean mixture
C) the stoichiometric mixture
D) none of the above

Question 12

The three main pollutants caused by a motor vehicle are carbon monoxide, hydrocarbons, and oxides of nitrogen.

Question 13

An emissions grade dynamometer allows a repair facility to simulate vehicle:

A) acceleration
B) steady state cruise
C) deceleration
D) all of the above

Question 14

Under the right conditions, a small amount of nitrogen can combine with oxygen in the combustion chamber to form oxides of nitrogen.

Question 15

Nitrogen makes up approximately 78 percent of the air we breathe.

Question 16

A faulty spark plug wire will cause HC emissions to increase.

Question 17

Oxygenated fuel is designed to reduce which of the following pollutants?

A) CO
B) HC
C) NO_X
D) all of the above

Question 18

Oxygen levels are highest when the vehicle is operating at the stoichiometric ratio.

Question 19

If a vehicle is repaired that failed a state emissions test for CO, what pollutant could potentially increase after the repair?

A) HC
B) NO_X
C) CO
D) O₂

Question 20

The levels of carbon dioxide exhaust emissions are highest when the air/fuel ratio is lean.

Question 21

As the air/fuel ratio becomes leaner, the higher the NO_X emissions will be until what point?

Question 22

How do Tier 2 emissions standards affect the automotive industry?

Question 23

What condition in the internal combustion engine will result in elevated nitrogen oxide (NO_X) levels?

Question 24

Write the general chemical formula for the dilution correction factor.

Question 25

List the five emission gases today's repair technician can measure with a shop-grade emissions analyzer, and what volume is each measured in?

Question 26

What is carbon monoxide the result of in the internal combustion engine?

Question 27

What should you do before beginning any diagnostic and repair procedure using an emissions analyzer, before performing any repairs?

Question 28

Describe CO emissions in relation to the air/fuel ratio, and explain how these emissions are formed.

Question 29

What are hydrocarbon emissions the result of?

Question 30

If the EGR intake passages are partially blocked but the EGR valve mechanically and electrically functions correctly, how and when would emissions be affected?

Question 31

How can you use the exhaust gas analyzer to determine the effectiveness of your repair?

Question 32

What are the only byproducts left after ideal combustion in the internal combustion gasoline engine?

Question 33

How and when are nitrogen oxide (NO_X) emissions formed in the internal combustion engine?

Question 34

Describe how HC emissions are formed, and explain the relationship of these emissions to the air/fuel ratio.

Question 35

What should you do to the secondary air injection system while diagnosing the cause of an emissions failure or performance problem?

Question 36

What gases is the five-gas emissions analyzer capable of monitoring?

Question 37

Explain the relationship of CO₂ emission levels to the air/fuel ratio in the internal combustion engine.

Question 38

Write the chemical formula for the actual combustion gas chemistry equation for the internal combustion engine.

Question 39

How can oxygen levels be used to indicate a rich air/fuel ratio?

Question 40

The CO emission levels are a moderate indicator of what type of air/fuel ratio?