Deck 32: Oxygen Sensors

Question 1

The voltage output of a zirconia oxygen sensor when the exhaust stream is lean (excess oxygen) is ______________.

A) Relatively high (close to 1 volt)
B) About in the middle of the voltage range
C) Relatively low (close to 0 volt)
D) Either a or b, depending on atmospheric pressure

Answer 1

When the exhaust stream is lean, the voltage output of zirconia (zirconium dioxide) oxygen sensor is lower than 0.45 V. And when the exhaust stream is rich, the voltage output of a zirconia oxygen sensor is greater than 0.45 V.
In this way, it is clear that the voltage output of the sensor is close to 0 volt when the exhaust stream is lean.
In the given options, option 'c' only justifies the explanation given above.
Hence, the correct option is
.

Question 2

How does an oxygen sensor detect oxygen levels in the exhaust?

Answer 2

The oxygen sensor produces a voltage signal and this voltage signal depends upon the volume of oxygen in the exhaust stream compared to the volume of atmospheric oxygen.
The electrolyte is solid and is the zirconium dioxide. There are also two porous platinum electrodes, which have the following functions.
• Exhaust side electrode is exposed to the exhaust stream.
• Ambient side electrode is exposed to outside air and is the signal electrode called as reference electrode.
If the exhaust is rich, oxygen from the electrodes wants to flow to the exhaust side electrode, which results in the production of a voltage.
If the exhaust is lean, oxygen flow is not needed, as a result, there is little if any electron movement and, therefore, no voltage is produced.
Contamination or corrosion in the zirconia oxygen sensor reduces the voltage signal output and consequently increases the oxygen level.
When the exhaust stream is lean, the voltage output of zirconia (zirconium dioxide) oxygen sensor is lower than 0.45 V. And when the exhaust stream is rich, the voltage output of zirconia oxygen sensor is greater than 0.45 V.
Exhaust oxygen content compared to the atmosphere oxygen is inversely proportional to the oxygen sensor voltage output. It means when first is low then the second will be high and vice-versa.

Question 3

A high O2S voltage could be due to a ______________.

A) Rich exhaust
B) Lean exhaust
C) Defective spark plug wire
D) Both a and c

Answer 3

A zirconia oxygen sensor (
) is known as two-step sensor because it has two states only. One state is obtained if the exhaust is richer and other state is obtained if the exhaust is leaner.
When the exhaust stream is lean, the voltage output of zirconia (zirconium dioxide) oxygen sensor is lower than 0.45 V. And when the exhaust stream is rich , the voltage output of zirconia oxygen sensor is greater than 0.45 V.
Thus, only the option '
' among the given options justifies the explanation given above.
Hence, the correct option is
.

Question 4

What are three basic designs of oxygen sensors and how many wires may be used for each?

Question 5

A low O2S voltage could be due to a ______________.

A) Rich exhaust
B) Lean exhaust
C) Defective spark plug wire
D) Both b and c

Question 6

What is the difference between open-loop and closed-loop engine operation?

Question 7

An oxygen sensor is being tested with a digital multimeter (DMM), using the MIN/MAX function. The readings are: minimum = 78 mV; maximum = 932 mV; average = 442 mV. Technician A says that the engine is operating correctly. Technician B says that the oxygen sensor is skewed too rich. 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

What are three ways oxygen sensors can be tested?

Question 9

An oxygen sensor is being tested using a digital storage oscilloscope (DSO). A good oxygen sensor should display how many transitions (switches) per second?

A) 1 to 5
B) 5 to 10
C) 10 to 15
D) 15 to 20

Question 10

How can the oxygen sensor be fooled and provide the wrong information to the PCM?

Question 11

A wide-band oxygen sensor was first used on a Honda in what model year?

A) 1992
B) 1996
C) 2000
D) 2006

Question 12

What is the purpose of a wide-band oxygen sensor?

Question 13

A wide-band oxygen sensor is capable of detecting the air-fuel mixture in the exhaust from ______________ (rich) to ______________ (lean).

A) 12:1; 15:1
B) 13:1; 16.7:1
C) 10:1; 23:1
D) 8:1; 18:1

Question 14

A wide-band oxygen sensor needs to be heated to what operating temperature?

A) 600°F (315°C)
B) 800°F (427°C)
C) 1,400°F (760°C)
D) 2,000°F (1,093°C)

Question 15

A wide-band oxygen sensor heater could draw how much current (amperes)?

A) 0.8 tO₂A
B) 2 tO₄A
C) 6 to 8 A
D) 8 to 10 A

Question 16

A P0133 DTC is being discussed. Technician A says that a defective heater circuit could be the cause. Technician B says that a contaminated sensor 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