Deck 19: Oxygen Sensors

Question 1

The sensor that must be warmed and functioning before the engine management computer will go to closed loop is the ________.

A) O2S
B) ECT sensor
C) BARO sensor
D) MAP sensor

Answer 1

A

Question 2

Where is sensor 1, bank 1 located?

A) On the same bank where number 1 cylinder is located
B) In the exhaust manifold
C) On the bank opposite cylinder number 1
D) Both A and B

Answer 2

D

Question 3

A heated Zirconia oxygen sensor will have how many wires?

A) 2
B) 3
C) 4
D) Either B or C

Answer 3

D

Question 4

When testing an oxygen sensor using a DSO (digital storage oscilloscope), how quickly should the voltage change when either propane is added to the intake stream or when a vacuum leak is created?

A) Less than 100 ms
B) 100-200 ms
C) 450-550 ms
D) 1-3 seconds

Question 5

Technician A says that an oxygen sensor produces a voltage output signal based on the oxygen content of the exhaust stream. Technician B says that if the exhaust has little oxygen the voltage of the oxygen sensor will be close to 0 volts. Which technician is correct?

A) Technician A only
B) Technician B only
C) Both technicians A and B
D) Neither technician A nor B

Question 6

Technician A says that oxygen sensors can have one, two, three, four, or more wires, depending on the style and design. Technician B says that if the exhaust has little oxygen, the voltage of the oxygen sensor will be close to 1 volt (1000 mV) and close to zero if there is high oxygen content in the exhaust. Which technician is correct?

A) Technician A only
B) Technician B only
C) Both technicians A and B
D) Neither technician A nor B

Question 7

Technician A says that oxygen sensors can be tested using a test light or dwell meter, or a scan tool. Technician B says that conditions can occur that cause the oxygen sensor to be fooled and give a false lean or false rich signal to the PCM. Which technician is correct?

A) Technician A only
B) Technician B only
C) Both technicians A and B
D) Neither technician A nor B

Question 8

A P0131 DTC is being discussed. Technician A says that an exhaust leak upstream of HO2S (bank 1) oxygen sensor could be the cause. Technician B says that an extremely rich air-fuel mixture could be the cause. Which technician is correct?

A) Technician A only
B) Technician B only
C) Both technicians A and B
D) Neither technician A nor B

Question 9

A P0132 DTC is being discussed. Technician A says that a defective HO2S could be the cause. Technician B says that an HO2S signal wire shorted-to-ground could be the cause. Which technician is correct?

A) Technician A only
B) Technician B only
C) Both technicians A and B
D) Neither technician A nor B

Question 10

When the concentration of oxygen on the exhaust side of the thimble is low (rich exhaust), a voltage of ________ is generated between the electrodes.

A) 0.60-1.0
B) 1.0-2.0
C) 0.25-0.50
D) 10-20

Question 11

A large amount of oxygen in the exhaust system causes the O2S (Oxygen sensor) to produce which of these?

A) High voltage
B) Abnormal readings
C) Low voltage
D) False readings

Question 12

What does the post, or downstream, oxygen sensor (HO2S) measure?

A) Amount of H₂O in front of the catalytic converter
B) Amount of H₂O behind the catalytic converter
C) Amount of oxygen in front of the catalytic converter
D) Amount of oxygen behind the catalytic converter

Question 13

With the vehicle in closed loop, the following post converter HO₂S scope pattern activity is seen. What does this indicate?

A) A lazy converter
B) A good converter
C) A missing converter
D) A bad converter

Question 14

With the vehicle in closed loop, the following post converter HO₂S scope pattern activity is seen. What does this indicate?

A) A lazy converter
B) A good converter
C) A bad converter
D) None of these

Question 15

The two internal chambers of a dual cell wide band oxygen sensor include ________ and ________.

A) inside; outside
B) single; dual
C) air reference; diffusion
D) Nernst; Pump

Question 16

When the air/fuel ratio is expressed as lambda, a lambda number of less than 1 indicates a(n) ________ exhaust.

A) rich
B) excessively cold
C) lean
D) excessively hot

Question 17

Technician A says that a wide-band oxygen sensor, also called a lean air-fuel (LAF) sensor, can detect air-fuel ratios from as rich as 10:1 to as lean as 23:1. Technician B says that the oxygen sensor signal determines fuel trim which is used to tailor the air-fuel mixture for the catalytic converter. Which technician is correct?

A) Technician A only
B) Technician B only
C) Both technicians A and B
D) Neither technician A nor B

Question 18

In some hybrid electric vehicles, the wide band oxygen sensor can cause the PCM to enter closed loop ________.

A) within 10 seconds of engine (ICE) start-up
B) as soon as the engine (ICE) starts
C) by the time the vehicle reaches 60 mph
D) within 2 minutes

Question 19

Most service information specifies that a(n) ________ be used when testing a wide band oxygen sensor.

A) vacuum hose
B) generic scan tool
C) HO₂S disconnect bypass tool
D) factory scan tool

Question 20

On a poorly running engine, the wide band oxygen sensor can be quickly checked by ________.

A) disconnecting the vehicle battery
B) disconnecting the sensor connector
C) jumping the connector with a jumper wire
D) jumping the connector with a flashlight battery