How does the oxygen sensor interact with exhaust gases and what are the implications of its voltage signals on air/fuel ratio on Mazda Millenia?

The oxygen sensor reacts with exhaust gases producing a voltage signal which is deciphered by the ECU to estimate the air fuel ratio whereby a low voltage value would indicate a lean condition whereas a high value would indicate a rich condition. The sensor is normally mounted on the exhaust manifold or pipes but in the case of turbocharged engines, the sensor is mounted inside the turbocharger. Certain Mazda engines can also possess various sensors such as front and rear sensors or pre-catalytic converter sensor and post-catalytic converter sensor to measure efficiency. In order to check the sensor output voltage, the engine must be running, and measurements of the sensor terminals should be taken, with certain voltage range of rich or lean conditions. In case of readings outside the ranges of specifications, the sensor is to be replaced. In the case of heater element resistance testing, then the sensor has to be disconnected, and the resistance between special terminals should be measured, with certain values of resistance at a given temperature being expected. When the readings are off range then the sensor might require replacement. To remove, the splash shielding that may be required should be removed, then the sensor wire connection should be detached, and the sensor should be loosened at the place where it is located. Other procedures in a turbocharged engine are switching off the battery and the sensor in the turbocharger. Removal should be reversed in regards to installation whereby proper specifications of torque are observed.

Genuine Mazda Millenia Oxygen Sensor

Oxygen O2 Sensor

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15 Oxygen Sensors found

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Mazda Millenia Oxygen Sensor Part Number: KJ02-18-861C-9U
$168.33 MSRP: $224.48
You Save: $56.15 (26%)
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Product Specifications
- Other Name: Sensor, Oxygen
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 1995-2002 Mazda Millenia | Base, Millennium Edition, S | 6 Cyl 2.3 L GAS
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Mazda Millenia Oxygen Sensor Part Number: KJ04-18-861B-9U
$185.00 MSRP: $246.72
You Save: $61.72 (26%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Sensor, Oxygen
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 1995-2002 Mazda Millenia | Base, Millennium Edition, S | 6 Cyl 2.3 L GAS
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Mazda Millenia Oxygen Sensor Part Number: KL1C-18-861-9U
$187.56 MSRP: $250.13
You Save: $62.57 (26%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Sensor, Oxygen
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 2001-2002 Mazda Millenia | Base | 6 Cyl 2.5 L GAS
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Mazda Millenia Oxygen Sensor Part Number: KL1D-18-861-9U
$187.56 MSRP: $250.13
You Save: $62.57 (26%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Sensor, Oxygen
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 2001-2002 Mazda Millenia | Base | 6 Cyl 2.5 L GAS
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Mazda Millenia Oxygen Sensor Part Number: TA36-18-861B-9U
$193.31 MSRP: $257.80
You Save: $64.49 (26%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Sensor, Oxygen
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 1995-1996 Mazda Millenia | Base, L | 6 Cyl 2.5 L GAS
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Mazda Millenia Oxygen Sensor Part Number: KJ01-18-861A-9U
$191.45 MSRP: $255.31
You Save: $63.86 (26%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Sensor, Oxygen
- Replaces: KJ01-18-861A
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 1995-2002 Mazda Millenia | Base, Millennium Edition, S | 6 Cyl 2.3 L GAS
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Mazda Millenia Oxygen Sensor Part Number: KJ03-18-861B-9U
$207.55 MSRP: $276.80
You Save: $69.25 (26%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Sensor, Oxygen
- Replaces: KJ03-18-861A-9U, KJ03-18-861A
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 1995-2002 Mazda Millenia | Base, Millennium Edition, S | 6 Cyl 2.3 L GAS
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Mazda Millenia Oxygen Sensor Part Number: KL62-18-861A-9U
$247.06 MSRP: $329.48
You Save: $82.42 (26%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Sensor, Oxygen
- Replaces: KL62-18-861A
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 1997-2002 Mazda Millenia | Base, L | 6 Cyl 2.5 L GAS
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Mazda Millenia Oxygen Sensor Part Number: KLL5-18-861B-9U
$39.85 MSRP: $52.31
You Save: $12.46 (24%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Sensor, Oxygen
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 1997-2002 Mazda Millenia | Base, L | 6 Cyl 2.5 L GAS
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Mazda Millenia Oxygen Sensor Part Number: TA37-18-861E-9U
$39.33 MSRP: $51.63
You Save: $12.30 (24%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Sensor, Oxygen
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 1995-1996 Mazda Millenia | Base, L | 6 Cyl 2.5 L GAS
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Mazda Millenia Oxygen Sensor Part Number: FS2V-18-861B-9U
Product Specifications
- Other Name: Sensor, Oxygen
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 2001-2002 Mazda Millenia | Base | 6 Cyl 2.5 L GAS
View related parts
Mazda Millenia Oxygen Sensor Part Number: KL1E-18-861A-9U
Product Specifications
- Other Name: Sensor, Oxygen
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 2001-2002 Mazda Millenia | Base | 6 Cyl 2.5 L GAS
View related parts
Mazda Millenia Oxygen Sensor Part Number: KL61-18-861A-9U
Product Specifications
- Other Name: Sensor, Oxygen
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 1997-2002 Mazda Millenia | Base, L | 6 Cyl 2.5 L GAS
View related parts
Mazda Millenia Oxygen Sensor Part Number: KLL6-18-861C
Product Specifications
- Other Name: Sensor, Oxygen
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 1997-2002 Mazda Millenia | Base, L | 6 Cyl 2.5 L GAS
View related parts
Mazda Millenia Oxygen Sensor Part Number: TA34-18-861B-9U
Product Specifications
- Other Name: Sensor, Oxygen
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 1995-1996 Mazda Millenia | Base, L | 6 Cyl 2.5 L GAS

Mazda Millenia Oxygen Sensor

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Mazda Millenia Oxygen Sensor Parts and Q&A

Oxygen Sensor
KJ03-18-861B-9U
Q: How does the oxygen sensor interact with exhaust gases and what are the implications of its voltage signals on air/fuel ratio on Mazda Millenia?
A:
The oxygen sensor reacts with exhaust gases producing a voltage signal which is deciphered by the ECU to estimate the air fuel ratio whereby a low voltage value would indicate a lean condition whereas a high value would indicate a rich condition. The sensor is normally mounted on the exhaust manifold or pipes but in the case of turbocharged engines, the sensor is mounted inside the turbocharger. Certain Mazda engines can also possess various sensors such as front and rear sensors or pre-catalytic converter sensor and post-catalytic converter sensor to measure efficiency. In order to check the sensor output voltage, the engine must be running, and measurements of the sensor terminals should be taken, with certain voltage range of rich or lean conditions. In case of readings outside the ranges of specifications, the sensor is to be replaced. In the case of heater element resistance testing, then the sensor has to be disconnected, and the resistance between special terminals should be measured, with certain values of resistance at a given temperature being expected. When the readings are off range then the sensor might require replacement. To remove, the splash shielding that may be required should be removed, then the sensor wire connection should be detached, and the sensor should be loosened at the place where it is located. Other procedures in a turbocharged engine are switching off the battery and the sensor in the turbocharger. Removal should be reversed in regards to installation whereby proper specifications of torque are observed.