What is the general information about oxygen sensors and their role on Mercury Mariner?

An oxygen sensor functions as a galvanic battery that generates a small voltage output based on the oxygen levels in exhaust gases, providing essential input for the feedback loop with the Powertrain Control Module (PCM) to maintain the ideal air/fuel ratio of 14.7:1 for optimal catalyst performance. Vehicles equipped with On-Board Diagnostics II (OBD-II) utilize two oxygen sensors-one before and one after the catalytic converter-to assess converter efficiency by comparing oxygen levels in the exhaust gases. Four-cylinder models feature one upstream and one downstream heated oxygen sensor, while V6 models have four heated sensors, with two for each cylinder head and multiple catalysts. All sensors are heated to reduce warm-up time, and care must be taken during servicing to avoid damaging the permanently attached pigtail and electrical connector, as well as to keep contaminants away from the sensor. When replacing an oxygen sensor, it is advisable to warm the engine to ease removal, apply anti-seize compound to the threads if reusing an old sensor, and ensure proper torque during installation. After reconnecting the battery, the PCM must relearn its idle and fuel trim strategy for optimal performance.

Genuine Mercury Mariner Oxygen Sensors

Oxygen O2 Sensor

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21 Oxygen Sensors found

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Mercury Mariner Sensor - Exhaust Gas - Oxygen
Part Number: BE5Z-9G444-B
$62.70 MSRP: $112.73
You Save: $50.03 (45%)
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Product Specifications
- Manufacturer Note: Rear
- Position: Lower
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2011 Mercury Mariner | 6 Cyl 3.0L OHC Duratec | 4AT CD4E, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
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Mercury Mariner Sensor - Hego
Part Number: 5L8Z-9F472-BA
$48.45 MSRP: $77.27
You Save: $28.82 (38%)
Ships in 1 Business Day
ADD TO CART
Product Specifications
- Manufacturer Note: Rear
- Position: Front
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2005-2010 Mercury Mariner | 4 Cyl 2.3L, 4 Cyl 2.3L Hybrid Gas/Electric DOHC, 4 Cyl 2.5L Duratec (110kW/150PS) | 4AT CD4E, 5-Speed Manual Transmission, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Four-Wheel Drive (Right Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive, Two-Wheel Drive (Left Hand Drive), Two-Wheel Drive (Right Hand Drive)
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Mercury Mariner Sensor - Hego
Part Number: 9E5Z-9F472-E
$81.51 MSRP: $160.73
You Save: $79.22 (50%)
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Product Specifications
- Other Name: Oxygen Sensor, Upper Oxygen Sensor
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2010-2011 Mercury Mariner | 4 Cyl 2.5L Duratec (110kW/150PS) | 6-Speed Automatic Transmission 6F Mid-Range, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
View related parts
Mercury Mariner Sensor - Exhaust Gas - Oxygen
Part Number: 5L8Z-9G444-F
$52.91 MSRP: $87.45
You Save: $34.54 (40%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Manufacturer Note: Rear
- Replaces: 5L8Z-9G444-H, 5L8Z-9G444-J
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2007-2010 Mercury Mariner | 6 Cyl 3.0L DOHC EFI Modular, 6 Cyl 3.0L OHC Duratec | 4AT CD4E, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
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Mercury Mariner Sensor Assembly
Part Number: YL8Z-9G444-CA
$54.56 MSRP: $90.18
You Save: $35.62 (40%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Sensor Assy
- Position: Passenger Side
- Replaced by: 5L8Z-9G444-A
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2005-2006 Mercury Mariner | 6 Cyl 3.0L DOHC EFI Modular | 4AT CD4E, 5-Speed Manual Transmission, 5-Speed Manual Transmission - AK, Four-Wheel Drive (Full Time) (Left Hand Drive), Four-Wheel Drive (Right Hand Drive), Left Hand Drive, Two-Wheel Drive (Left Hand Drive), Two-Wheel Drive (Right Hand Drive)
View related parts
Mercury Mariner Sensor - Exhaust Gas - Oxygen
Part Number: BE5Z-9G444-A
$72.60 MSRP: $120.00
You Save: $47.40 (40%)
Ships in 1 Business Day
ADD TO CART
Product Specifications
- Position: Front
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2011 Mercury Mariner | 4 Cyl 2.5L PFI Gas/Electric, 6 Cyl 3.0L OHC Duratec | 4AT CD4E, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
View related parts
Mercury Mariner Sensor - Hego
Part Number: 8F9Z-9F472-B
$94.27 MSRP: $155.82
You Save: $61.55 (40%)
Ships in 1 Business Day
ADD TO CART
Product Specifications
- Manufacturer Note: Front Or Rear
- Position: Upper
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2009-2011 Mercury Mariner | 4 Cyl 2.5L PFI Gas/Electric | 4AT CD4E, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
View related parts
Mercury Mariner Sensor - Hego
Part Number: 9E5Z-9F472-D
$103.29 MSRP: $170.73
You Save: $67.44 (40%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Position: Front And Rear
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2010-2011 Mercury Mariner | 6 Cyl 3.0L OHC Duratec | 4AT CD4E, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
View related parts
Mercury Mariner Sensor - Hego
Part Number: 5C5Z-9F472-AA
$49.72 MSRP: $82.18
You Save: $32.46 (40%)
Ships in 1 Business Day
ADD TO CART
Product Specifications
- Position: Passenger Side
- Replaced by: GU2Z-9G444-A
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2007-2008 Mercury Mariner | 6 Cyl 3.0L DOHC EFI Modular | 4AT CD4E, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
View related parts
Mercury Mariner Sensor - Hego
Part Number: XC2Z-9F472-AA
$49.72 MSRP: $82.18
You Save: $32.46 (40%)
Ships in 1 Business Day
ADD TO CART
Product Specifications
- Position: Passenger Side
- Replaced by: GU2Z-9G444-A
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2005-2006 Mercury Mariner | 6 Cyl 3.0L DOHC EFI Modular | 4AT CD4E, 5-Speed Manual Transmission, 5-Speed Manual Transmission - AK, Four-Wheel Drive (Full Time) (Left Hand Drive), Four-Wheel Drive (Right Hand Drive), Left Hand Drive, Two-Wheel Drive (Left Hand Drive), Two-Wheel Drive (Right Hand Drive)
View related parts
Mercury Mariner Sensor - Exhaust Gas - Oxygen
Part Number: 5W6Z-9G444-BA
$49.72 MSRP: $82.18
You Save: $32.46 (40%)
Ships in 1 Business Day
ADD TO CART
Product Specifications
- Position: Front
- Replaced by: GU2Z-9G444-A
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2008-2010 Mercury Mariner | 4 Cyl 2.3L, 4 Cyl 2.5L PFI Gas/Electric, 6 Cyl 3.0L OHC Duratec | 4AT CD4E, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
- 2005-2006 Mercury Mariner | 4 Cyl 2.3L | 4AT CD4E, 5-Speed Manual Transmission, 5-Speed Manual Transmission - AK, Four-Wheel Drive (Full Time) (Left Hand Drive), Four-Wheel Drive (Right Hand Drive), Left Hand Drive, Two-Wheel Drive (Left Hand Drive), Two-Wheel Drive (Right Hand Drive)
View related parts
Mercury Mariner Sensor - Hego
Part Number: 5L8Z-9F472-AA
$40.16 MSRP: $79.82
You Save: $39.66 (50%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Manufacturer Note: Rear
- Position: Front
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2009 Mercury Mariner | 6 Cyl 3.0L OHC Duratec | 4AT CD4E, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
View related parts
Mercury Mariner Sensor - Exhaust Gas - Oxygen
Part Number: 5L8Z-9G444-K
$73.59 MSRP: $121.64
You Save: $48.05 (40%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Lower Oxygen Sensor, Oxygen Sensor
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2009-2010 Mercury Mariner | 4 Cyl 2.5L Duratec (110kW/150PS) | 4AT CD4E, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
View related parts
Mercury Mariner Sensor - Exhaust Gas - Oxygen
Part Number: 5M6Z-9G444-A
$62.59 MSRP: $99.82
You Save: $37.23 (38%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Replaces: 1R3Z-9G444-DA
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2005-2008 Mercury Mariner | 4 Cyl 2.3L Hybrid Gas/Electric DOHC | 4AT CD4E, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
View related parts
Mercury Mariner Sensor - Exhaust Gas - Oxygen
Part Number: BL8Z-9G444-A
$71.50 MSRP: $118.18
You Save: $46.68 (40%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Lower Oxygen Sensor, Oxygen Sensor
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2011 Mercury Mariner | 4 Cyl 2.5L Duratec (110kW/150PS) | 4AT CD4E, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
View related parts
Mercury Mariner Sensor - Exhaust Gas - Oxygen
Part Number: 5L8Z-9G444-H
$52.91 MSRP: $87.45
You Save: $34.54 (40%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Manufacturer Note: Rear
- Position: Front
- Replaced by: 5L8Z-9G444-F
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2007 Mercury Mariner | 6 Cyl 3.0L DOHC EFI Modular | 4AT CD4E, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
View related parts
Mercury Mariner Sensor - Exhaust Gas - Oxygen
Part Number: 5L8Z-9G444-J
$52.91 MSRP: $87.45
You Save: $34.54 (40%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Position: Front
- Replaced by: 5L8Z-9G444-F
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2008 Mercury Mariner | 6 Cyl 3.0L DOHC EFI Modular | 4AT CD4E, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
View related parts
Mercury Mariner Sensor - Exhaust Gas - Oxygen
Part Number: 5L8Z-9G444-G
$54.56 MSRP: $90.18
You Save: $35.62 (40%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Manufacturer Note: Rear
- Replaced by: 5L8Z-9G444-A
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2007-2008 Mercury Mariner | 6 Cyl 3.0L DOHC EFI Modular | 4AT CD4E, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
View related parts
Mercury Mariner Sensor - Exhaust Gas - Oxygen
Part Number: 5F9Z-9G444-BA
$49.72 MSRP: $82.18
You Save: $32.46 (40%)
Ships in 1 Business Day
ADD TO CART
Product Specifications
- Manufacturer Note: Rear
- Replaced by: GU2Z-9G444-A
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2007-2008 Mercury Mariner | 4 Cyl 2.3L | 4AT CD4E, 5-Speed Manual Transmission - AK, 6-Speed Automatic Transmission 6F Mid-Range, CVT Auto Trans Powersplit Elec, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive
View related parts
Mercury Mariner Sensor - Hego
Part Number: BE5Z-9F472-B
$67.26 MSRP: $107.27
You Save: $40.01 (38%)
Ships in 1-3 Business Days
ADD TO CART
Product Specifications
- Other Name: Oxygen Sensor, Upper Oxygen Sensor
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2011 Mercury Mariner | 4 Cyl 2.5L Duratec (110kW/150PS) | 5-Speed Manual Transmission - AK, Four-Wheel Drive (Full Time) (Left Hand Drive), Front-Wheel Drive (Left Hand Drive), Left Hand Drive

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Mercury Mariner Oxygen Sensors

We provide a wide range of Mercury Mariner Oxygen Sensors at the best prices possible. If you need Mercury Mariner Oxygen Sensors, you can shop with confidence on our website. All our OEM parts come with a manufacturer's warranty and are delivered to your door step with a fast delivery service.

Mercury Mariner Oxygen Sensors Parts Questions & Experts Answers

Sensor - Hego
5L8Z-9F472-BA
Q: What is the general information about oxygen sensors and their role on Mercury Mariner?
A: An oxygen sensor functions as a galvanic battery that generates a small voltage output based on the oxygen levels in exhaust gases, providing essential input for the feedback loop with the Powertrain Control Module (PCM) to maintain the ideal air/fuel ratio of 14.7:1 for optimal catalyst performance. Vehicles equipped with On-Board Diagnostics II (OBD-II) utilize two oxygen sensors-one before and one after the Catalytic Converter-to assess converter efficiency by comparing oxygen levels in the exhaust gases. Four-cylinder models feature one upstream and one downstream heated oxygen sensor, while V6 models have four heated sensors, with two for each cylinder head and multiple catalysts. All sensors are heated to reduce warm-up time, and care must be taken during servicing to avoid damaging the permanently attached pigtail and electrical connector, as well as to keep contaminants away from the sensor. When replacing an oxygen sensor, it is advisable to warm the engine to ease removal, apply anti-seize compound to the threads if reusing an old sensor, and ensure proper torque during installation. After reconnecting the battery, the PCM must relearn its idle and fuel trim strategy for optimal performance.

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2011 Oxygen Sensors 2010 Oxygen Sensors 2009 Oxygen Sensors 2008 Oxygen Sensors 2007 Oxygen Sensors 2006 Oxygen Sensors 2005 Oxygen Sensors