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Oxygen Sensors

8874 items

Shop best-selling oxygen sensors for Ford, Chevy, Honda, Nissan, Toyota, and more. Direct-fit O2 sensors with fast response, improved MPG, and reliable emissions performance.

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Upstream & Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0242Upstream & Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0242
A-Premium®Part # APOS0242
Upstream & Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0242
4.5651 Reviews
$46.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 1997 - 2000 Honda Civic, 1997 - 1997 Honda Civic, 1997 - 1997 Honda Civic del Sol
Check if this fits your vehicle
Installation PositionUpstream & Downstream
Item LocatedUnited States
ConditionNew
item #1004A8UX
Note
This item not fit for Manual Transmission.
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Upstream or Downstream O2 Oxygen Sensor | 1-Pc Direct-Fit | Heated | A-Premium APOS1088
A-Premium®Part # APOS1088
Upstream or Downstream O2 Oxygen Sensor | 1-Pc Direct-Fit | Heated | A-Premium APOS1088
4.5651 Reviews
$30.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2021 - 2023 Kia Forte, 2021 - 2023 Kia Seltos, 2019 - 2021 Hyundai Tucson, 2019 - 2020 Kia Forte, 2018 - 2021 Hyundai Kona, 2017 - 2020 Kia Optima, 2016 - 2019 Hyundai Sonata, 2014 - 2016 Hyundai Elantra, 2014 - 2016 Hyundai Elantra, 2014 - 2016 Kia Forte, 2014 - 2016 Kia Forte, 2014 - 2016 Kia Forte Koup, 2014 - 2016 Kia Forte5, 2014 - 2014 Hyundai Elantra Coupe, 2014 - 2014 Hyundai Elantra GT, 2013 - 2013 Hyundai Elantra Coupe, 2013 - 2013 Hyundai Elantra GT, 2011 - 2013 Hyundai Elantra
Check if this fits your vehicle
Installation PositionUpstream or Downstream
Item LocatedUnited States
ConditionNew
item #10051AVD
Note
Oxygen Sensor - B1S2 Indicates Bank 1 Sensor 2.
【Note-1】For 2019-2021 Hyundai Tucson & 2021-2023 Kia Seltos L4 2.0L, this item fits FWD(Front Wheel Drive) only, Not fit AWD(All Wheel Drive).
【Note-2】This item not fits 2016-2019 Hyundai Sonata L4 2.0L GAS models.
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Downstream O2 Oxygen Sensor | 1-Pc Direct-Fit | Heated | A-Premium OS084
A-Premium®Part # OS084
Downstream O2 Oxygen Sensor | 1-Pc Direct-Fit | Heated | A-Premium OS084
4.5651 Reviews
$49.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2013 - 2013 Nissan Altima, 2013 - 2013 Nissan Rogue, 2012 - 2012 Nissan Altima, 2011 - 2011 Nissan Altima, 2008 - 2012 Nissan Rogue, 2007 - 2011 Nissan Altima, 2007 - 2010 Nissan Altima
Check if this fits your vehicle
Installation PositionDownstream
Item LocatedUnited States
ConditionNew
item #10031U8Q
Note
O2 Sensor - B1S2 Indicates Bank 1 Sensor 2, B1S3 Indicates Bank 1 Sensor 3.
【Note-1】For 2007-2012 Nissan Altima & 2008-2012 Nissan Rogue, it fits with California Emissions, not fit with Federal Emissions.
【Note-2】For 2007-2011 Nissan Altima & 2008-2012 Nissan Rogue, it fits After Secondary Cat, not After Primary Cat or Before Primary Cat.
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Upstream & Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0859
A-Premium®Part # APOS0859
Upstream & Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0859
4.5651 Reviews
$89.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2013 - 2018 Lexus ES300h, 2013 - 2018 Toyota RAV4, 2013 - 2018 Toyota RAV4, 2013 - 2018 Toyota RAV4, 2013 - 2018 Toyota RAV4, 2013 - 2018 Toyota RAV4, 2013 - 2018 Toyota RAV4, 2013 - 2018 Toyota RAV4, 2013 - 2018 Toyota RAV4, 2013 - 2018 Toyota RAV4, 2012 - 2017 Toyota Camry, 2011 - 2016 Scion tC
Check if this fits your vehicle
Quantity2
Installation PositionUpstream & Downstream
Item LocatedUnited States
ConditionNew
item #1001GT6A
Show less
Downstream Driver & Passenger O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0412
A-Premium®Part # APOS0412
Downstream Driver & Passenger O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0412
4.5651 Reviews
$69.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2015 - 2019 INFINITI Q70L, 2015 - 2015 INFINITI Q40, 2014 - 2019 INFINITI Q70, 2014 - 2015 Nissan Rogue Select, 2014 - 2014 INFINITI Q70, 2014 - 2014 INFINITI QX50, 2014 - 2014 INFINITI QX70, 2014 - 2014 INFINITI QX70, 2014 - 2014 Nissan Cube, 2013 - 2013 INFINITI EX37, 2013 - 2013 INFINITI FX37, 2013 - 2013 Nissan Rogue, 2012 - 2012 INFINITI FX35, 2011 - 2013 INFINITI M37, 2011 - 2013 INFINITI M56, 2011 - 2012 INFINITI G25, 2011 - 2011 Nissan Cube, 2011 - 2011 Nissan Murano, 2011 - 2011 Nissan Quest, 2009 - 2014 Nissan Maxima
Check if this fits your vehicle
Quantity2
Installation PositionDownstream Driver & Passenger
Item LocatedUnited States
ConditionNew
item #10049UVC
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Downstream O2 Oxygen Sensor | 1-Pc Direct-Fit | Heated | A-Premium APOS1397
A-Premium®Part # APOS1397
Downstream O2 Oxygen Sensor | 1-Pc Direct-Fit | Heated | A-Premium APOS1397
4.5651 Reviews
$28.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2020 - 2020 Subaru Legacy, 2020 - 2020 Subaru Outback, 2019 - 2020 Subaru Ascent, 2015 - 2020 Subaru WRX, 2014 - 2018 Subaru Forester
Check if this fits your vehicle
Installation PositionDownstream
Item LocatedUnited States
ColorBlack
ConditionNew
item #1004WWTN
Note
O2 Sensor - Bank 1 Sensor 2.
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Downstream Front & Rear O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0399
A-Premium®Part # APOS0399
Downstream Front & Rear O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0399
4.5651 Reviews
$52.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2006 - 2008 Honda Ridgeline, 2006 - 2007 Honda Accord, 2005 - 2010 Honda Odyssey, 2005 - 2008 Acura RL, 2005 - 2008 Honda Pilot, 2005 - 2007 Honda Accord, 2004 - 2006 Acura TL, 2003 - 2006 Acura MDX, 2003 - 2005 Honda Accord, 2003 - 2005 Honda Accord
Check if this fits your vehicle
Quantity2
Installation PositionDownstream Front & Rear
Item LocatedUnited States
ConditionNew
item #10049QS1
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Downstream O2 Oxygen Sensor | 1-Pc Direct-Fit | Heated | A-Premium APOS0565
A-Premium®Part # APOS0565
Downstream O2 Oxygen Sensor | 1-Pc Direct-Fit | Heated | A-Premium APOS0565
4.5651 Reviews
$34.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2018 - 2018 Nissan Altima, 2018 - 2018 Nissan Altima, 2018 - 2018 Nissan Altima, 2018 - 2018 Nissan Altima, 2014 - 2017 Nissan Altima, 2013 - 2013 Nissan Altima
Check if this fits your vehicle
Installation PositionDownstream
Item LocatedUnited States
ConditionNew
item #10032L54
Note
【Note-1】For 2013 Nissan Altima, it only fits for 4-Door, not 2-Door.
【Note-2】For 2018 Nissan Altima, it only fits for SV/SR/SL/S Model, not other Model.
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Downstream O2 Oxygen Sensor | 1-Pc Direct-Fit | Heated | A-Premium APOS0108
A-Premium®Part # APOS0108
Downstream O2 Oxygen Sensor | 1-Pc Direct-Fit | Heated | A-Premium APOS0108
4.5651 Reviews
$33.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2024 - 2024 Hyundai Elantra, 2022 - 2023 Hyundai Elantra, 2022 - 2022 Hyundai Ioniq, 2021 - 2023 Kia Seltos, 2021 - 2022 Kia Niro, 2021 - 2021 Hyundai Elantra, 2018 - 2021 Hyundai Kona, 2018 - 2018 Hyundai Elantra GT, 2017 - 2021 Hyundai Ioniq, 2017 - 2020 Hyundai Elantra, 2017 - 2020 Hyundai Elantra, 2017 - 2020 Kia Niro, 2016 - 2020 Kia Optima, 2016 - 2018 Hyundai Tucson, 2016 - 2017 Hyundai Veloster, 2015 - 2019 Hyundai Sonata, 2015 - 2019 Kia Rio, 2014 - 2018 Kia Forte5, 2014 - 2016 Kia Forte Koup, 2012 - 2020 Kia Soul
Check if this fits your vehicle
Installation PositionDownstream
Item LocatedUnited States
ConditionNew
item #100320QN
Note
O2 Sensor - Bank 1 Sensor 2.
【Note-1】 For 2021-2023 Hyundai Elantra, it fits FULL HYBRID EV-GAS (FHEV), not GAS.
【Note-2】 For 2017-2021 Hyundai Ioniq, it fits Hybrid Model only.
【Note-3】 For 2012-2015 Hyundai Veloster, it fits Naturally Aspirated, not Turbocharged.
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Upstream & Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS1548
A-Premium®Part # APOS1548
Upstream & Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS1548
4.5651 Reviews
$62.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2009 - 2011 Chevrolet HHR, 2007 - 2009 Pontiac G5, 2007 - 2008 Pontiac G5, 2007 - 2007 Saturn Vue, 2006 - 2011 Chevrolet HHR, 2006 - 2008 Chevrolet Cobalt, 2006 - 2007 Saturn Ion, 2006 - 2007 Saturn Vue, 2005 - 2010 Chevrolet Cobalt, 2005 - 2007 Saturn Ion
Check if this fits your vehicle
Installation PositionUpstream & Downstream
Item LocatedUnited States
ConditionNew
item #10049S0E
Note
O2 Sensor - B1S1 Indicates Bank 1 Sensor 1, B1S2 Indicates Bank 1 Sensor 2.
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Upstream & Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0185
A-Premium®Part # APOS0185
Upstream & Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0185
4.5651 Reviews
$70.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2002 - 2004 Honda CR-V
Check if this fits your vehicle
Installation PositionUpstream & Downstream
Item LocatedUnited States
ConditionNew
item #10049U7Y
Note
O2 Sensor - (Upstream)：B1S1 Indicates Bank 1 Sensor 1,(Downstream)：B1S2 Indicates Bank 1 Sensor 2.
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Downstream O2 Oxygen Sensor | 1-Pc Direct-Fit | Heated | A-Premium OS153
A-Premium®Part # OS153
Downstream O2 Oxygen Sensor | 1-Pc Direct-Fit | Heated | A-Premium OS153
4.5651 Reviews
$22.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2004 - 2008 Acura TSX, 2003 - 2007 Honda Accord
Check if this fits your vehicle
Installation PositionDownstream
Item LocatedUnited States
ConditionNew
item #10031D4C
Note
O2 Sensor - Bank 1 Sensor 2.
This item fits Engine L4 2.4L only, not V6 3.0L.
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Upstream & Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0903
A-Premium®Part # APOS0903
Upstream & Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0903
4.5651 Reviews
$88.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2015 - 2015 Honda Civic, 2014 - 2015 Honda Civic, 2012 - 2013 Honda Civic, 2012 - 2013 Honda Civic, 2006 - 2011 Honda Civic, 2006 - 2011 Honda Civic
Check if this fits your vehicle
Quantity2
Installation PositionUpstream & Downstream
Item LocatedUnited States
ConditionNew
item #1001H68K
Show less
Upstream & Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0871
A-Premium®Part # APOS0871
Upstream & Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0871
4.5651 Reviews
$74.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2003 - 2007 Honda Accord
Check if this fits your vehicle
Installation PositionUpstream & Downstream
Item LocatedUnited States
ConditionNew
item #1001GPL2
Note
Oxygen Senor - Upstream Bank 1 Sensor 1, Downstream Bank 1 Sensor 2.
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Downstream Driver & Passenger O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium OS144
A-Premium®Part # OS144
Downstream Driver & Passenger O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium OS144
4.5651 Reviews
$46.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2015 - 2021 Nissan NV1500, 2015 - 2021 Nissan NV2500, 2015 - 2021 Nissan NV3500, 2012 - 2014 Nissan NV1500, 2012 - 2014 Nissan NV2500, 2012 - 2014 Nissan NV3500, 2009 - 2012 Suzuki Equator, 2005 - 2012 Nissan Frontier, 2005 - 2012 Nissan Pathfinder, 2005 - 2012 Nissan Xterra
Check if this fits your vehicle
Installation PositionDownstream Driver & Passenger
Item LocatedUnited States
ConditionNew
item #10032131
Note
【Note-1】 It comes with 4-Blade, not 6-Blade.
【Note-2】It fits for V6 4.0L, not other Engine.
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Downstream Front & Rear O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0238
A-Premium®Part # APOS0238
Downstream Front & Rear O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0238
4.5651 Reviews
$46.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2012 - 2014 Acura TL, 2012 - 2012 Honda Crosstour, 2011 - 2013 Honda Odyssey, 2011 - 2013 Honda Odyssey, 2011 - 2013 Honda Odyssey, 2010 - 2014 Acura TSX, 2010 - 2011 Honda Accord, 2010 - 2011 Honda Accord Crosstour, 2009 - 2013 Honda Pilot, 2009 - 2013 Honda Ridgeline, 2009 - 2011 Acura TL, 2009 - 2010 Acura RL, 2008 - 2010 Honda Odyssey, 2008 - 2009 Honda Accord, 2007 - 2011 Acura TL, 2007 - 2009 Acura MDX, 2007 - 2008 Acura TL
Check if this fits your vehicle
Installation PositionDownstream Front & Rear
Item LocatedUnited States
ConditionNew
item #10049ZGC
Note
【Note-1】For 2012-2014 Acura TL V6 3.7L fit the model with Manual Transmission.
【Note-2】For 2008-2009 Honda Accord V6 3.5L fit the model with California Emission.
【Note-3】For 2011-2013 Honda Accord V6 3.5L fit EX,LX,EX-L Models only.
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Upstream & Downstream O2 Oxygen Sensor | 4-Pc Direct-Fit | Heated | A-Premium OS107
A-Premium®Part # OS107
Upstream & Downstream O2 Oxygen Sensor | 4-Pc Direct-Fit | Heated | A-Premium OS107
4.5651 Reviews
$79.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2004 - 2004 Isuzu Axiom, 2004 - 2004 Isuzu Rodeo, 2002 - 2005 Chevrolet Blazer, 2002 - 2004 Isuzu Rodeo, 2002 - 2003 Isuzu Rodeo Sport, 2002 - 2002 Cadillac Escalade, 2002 - 2002 Chevrolet Avalanche 1500, 2002 - 2002 GMC Sonoma, 2002 - 2002 Honda Passport, 2000 - 2002 Chevrolet Silverado 1500, 2000 - 2002 Chevrolet Silverado 1500, 2000 - 2002 Chevrolet Suburban 1500, 2000 - 2002 Chevrolet Tahoe, 2000 - 2002 Chevrolet Tahoe, 2000 - 2002 GMC Sierra 1500, 2000 - 2002 GMC Sierra 1500, 2000 - 2002 GMC Yukon, 2000 - 2002 GMC Yukon, 2000 - 2002 GMC Yukon XL 1500, 2000 - 2000 Chevrolet Silverado 2500
Check if this fits your vehicle
Installation PositionUpstream & Downstream
Item LocatedUnited States
ConditionNew
item #10030VD5
Note
This item only fit for Canada Built Vehicle: Avalanche / Silverado / Suburban/ Tahoe/ Sierra/ Yukon/ Yukon XL.
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Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium OS106
A-Premium®Part # OS106
Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium OS106
4.5651 Reviews
$42.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2011 - 2013 BMW 335is, 2011 - 2011 BMW 1 Series M, 2010 - 2011 BMW 323i, 2009 - 2016 BMW Z4, 2008 - 2013 BMW 128i, 2008 - 2010 BMW 135i, 2008 - 2010 BMW 528i, 2008 - 2008 BMW 528xi, 2007 - 2013 BMW 328i, 2007 - 2010 BMW 335i, 2007 - 2010 BMW X3, 2007 - 2010 BMW X5, 2007 - 2008 BMW 328xi, 2007 - 2008 BMW 335xi, 2006 - 2008 BMW Z4, 2006 - 2006 BMW 325i, 2006 - 2006 BMW 325xi, 2006 - 2006 BMW 330i, 2006 - 2006 BMW 330xi
Check if this fits your vehicle
Installation PositionDownstream
Item LocatedUnited States
ConditionNew
item #10031TLU
Note
O2 Sensor - Cylinder 1-3, Cylinder 4-6.
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Upstream & Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0872
A-Premium®Part # APOS0872
Upstream & Downstream O2 Oxygen Sensor | 2-Pc Direct-Fit | Heated | A-Premium APOS0872
4.5651 Reviews
$81.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2016 - 2020 Subaru Crosstrek, 2015 - 2015 Subaru XV Crosstrek, 2014 - 2014 Subaru XV Crosstrek, 2013 - 2020 Subaru Forester, 2013 - 2019 Subaru Legacy, 2013 - 2019 Subaru Outback, 2013 - 2013 Subaru XV Crosstrek, 2012 - 2020 Subaru Impreza
Check if this fits your vehicle
Installation PositionUpstream & Downstream
Item LocatedUnited States
ConditionNew
item #1001GPGN
Note
O2 Sensor - Bank 1 Sensor 1 (B1S1), Bank 1 Sensor 2 (B1S2).
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Upstream & Downstream O2 Oxygen Sensor | 4-Pc Direct-Fit | Heated | A-Premium OS103
A-Premium®Part # OS103
Upstream & Downstream O2 Oxygen Sensor | 4-Pc Direct-Fit | Heated | A-Premium OS103
4.5651 Reviews
$96.99
Enter ZIP codeFree standard shipping
3-year warranty
90 days free return
Fits 2009 - 2009 Jeep Wrangler, 2007 - 2009 Jeep Wrangler, 2007 - 2009 Jeep Wrangler, 2007 - 2009 Jeep Wrangler, 2007 - 2009 Jeep Wrangler, 2007 - 2009 Jeep Wrangler, 2007 - 2009 Jeep Wrangler
Check if this fits your vehicle
Quantity4
Installation PositionUpstream & Downstream
Item LocatedUnited States
ConditionNew
item #10031NG5
Show less
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Your vehicle’s oxygen sensor (also known as O2 sensors) plays a critical role in engine performance, fuel efficiency, and emissions control. By continuously measuring the amount of unburned oxygen in the exhaust, the oxygen sensor sends real-time feedback to your engine control unit (ECU), ensuring the perfect air-fuel mixture.

When an oxygen sensor fails, your engine essentially runs “blind,” leading to poor fuel economy, rough idling, reduced performance, and a persistent check engine light. A timely front oxygen sensor replacement or replacement of a faulty upstream oxygen sensor or downstream oxygen sensor can restore optimal driving conditions and help you pass emissions tests with ease.

 

Why Choose A-Premium Oxygen Sensors?

Unlike universal parts that require cutting and splicing wires, A-Premium O2 sensors are engineered for direct plug-and-play installation.

  • OEM-style connectors for seamless fit
  • Pre-coated anti-seize threads for easy installation
  • Laser-welded body construction for durability
  • High-temperature sintered coating for long service life
  • Premium insulation sheathing and impact-resistant design
  • Slotted guard tube for sensor protection
  • High heat dissipation structure for extreme environments

 

Advanced Performance & Precision

A-Premium oxygen sensor technology ensures fast, accurate, and stable performance:

Performance & Response

  • ≤200ms fast response time
  • High-efficiency oxygen sensing
  • Zirconia sensing element
  • Real-time signal feedback

Precision & Control

  • Real-time exhaust tracking
  • Accurate combustion control
  • Stable signal output

Efficiency & Engine Benefits

  • Improved fuel efficiency
  • Enhanced engine performance
  • Reduced harmful emissions
  • Extended engine lifespan

Environmental Adaptability

  • Operating range: -40°F to 266°F
  • Air-tight sealing design
  • Stable performance under harsh conditions

 

3 Symptoms of a Bad Oxygen Sensor

Because O2 sensors operate in extreme heat and carbon-rich environments, they naturally degrade over time.

  • Check Engine Light (CEL): Common codes include P0135, P0171, and P0420. These often point to issues with an upstream oxygen sensor or oxygen sensor bank 1.
  • Poor Fuel Economy: A faulty oxygen sensor may cause a rich fuel mixture, dramatically lowering MPG. 20-40% worse fuel economy overnight.
  • Rough Idle & Stalling: Incorrect readings from your downstream oxygen sensor or upstream sensor can disrupt engine stability.
  • Rotten egg smell: Catalytic converter overheating from bad fuel mixture

 

Understanding O2 Sensor Positions: Upstream vs Downstream

Modern vehicles may have multiple oxygen sensor units, making it essential to identify the correct one:

  • Oxygen Sensor Bank 1vs Bank 2 
    • oxygen sensor bank 1 refers to the side of the engine with Cylinder #1
    • Bank 2 is the opposite side
  • Upstream Oxygen Sensor(Sensor 1) 
    • Located before the catalytic converter
    • Controls air-fuel ratio
    • Most common need for front oxygen sensor replacement
  • Downstream Oxygen Sensor(Sensor 2) 
    • Located after the catalytic converter
    • Monitors emissions system efficiency

Tip: Always match your diagnostic code to the correct upstream oxygen sensor or downstream oxygen sensor before purchasing.

 

Complete Your Emissions Repair

Replacing your oxygen sensor is often part of a larger emissions system fix. Consider inspecting these related components:

 

Shop by Popular Makes

To help you quickly find the right oxygen sensor, explore our most popular vehicle-specific options:

Browse our most searched and best-selling vehicle-specific oxygen sensor options to quickly locate the right fit for your car.

Popular Oxygen Sensor by Model

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Can You Clean an O2 Sensor to Make It Work Again?

Cleaning an O2 sensor rarely fixes internal faults or chemical poisoning. Learn to diagnose root causes, interpret deposit colors, avoid damaging methods, and determine when replacement is the only reliable solution for engine health.

Sep 22, 2026

P0031 Code: Bank 1 Sensor 1 Heater Circuit Low

Diagnose P0031 (Bank 1 Sensor 1 Heater Circuit Low) with our step-by-step guide. Identify causes like faulty wiring, blown fuses, or bad sensors. Test resistance and power safely to avoid unnecessary replacements and ensure accurate repairs.

Sep 22, 2026

P0138 Code: O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)

P0138 indicates high voltage in the Bank 1 Sensor 2 O2 circuit. Don't just replace the sensor; diagnose wiring shorts, connector issues, or rich fuel conditions first. Learn proper location, symptoms, and step-by-step fixes to avoid costly mistakes.

Sep 10, 2026

How to Remove a Stuck O2 Sensor Without Damaging the Sensor Bung

Remove stuck O2 sensors safely without damaging the bung. Learn why they seize, proper tools, and step-by-step techniques using penetrating oil and controlled force. Avoid rounded hexes and costly exhaust repairs with these expert tips.

Sep 07, 2026

Are Upstream and Downstream O2 Sensors Interchangeable? How to Tell Them Apart

The short answer is no. This guide breaks down the exact mechanical and electrical differences between these two sensors. By reading on, you will gain master-tech diagnostic insights, learn a foolproof 4-step checklist to tell them apart instantly

Aug 28, 2026