Walker 350-341018 Oxygen Sensor - Downstream
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Walker
 Walker Products Aftermarket

Walker 350-341018 Oxygen Sensor - Downstream

Brand Walker 350-341018
Position Downstream
Connector Gender Male
Connector Shape Radiused Polygon
Mounting Type Threaded
Overall Length 24.60
Sensor Type Heated
Thread Diameter 18.0
Universal Or Specific Fit Specific
Wire Gauge Measurement 20
Wire Quantity 4
Wiring Harness Length 21.65
Product line Walker Products Aftermarket
Fits BMW and Mini · 87 vehicles

OE replacement. Engineered as a direct-fit oxygen sensor for the specified application.

Heated sensor. Helps deliver faster feedback to the ECU for precise engine management.

Threaded mount. Installs with a secure, threaded connection.

$70.31Free shipping
In stock · usually ships same day before 1pm CST
Step 1 — Confirm fitment
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Step 2 — Quantity
Order total $70.31
Free shipping to the continental U.S.
Free returns within 60 days if it doesn't fit when fitment is verified.
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Walker 350-341018 Oxygen Sensor for BMW and Mini

Walker Products 350-341018 is a heated downstream oxygen sensor built as a specific-fit OE replacement for select BMW and Mini applications. It is engineered to deliver the diagnostic feedback the ECU expects, helping maintain proper fuel control and emissions monitoring.

Key Features

  • Heated oxygen sensor for downstream placement
  • Specific-fit design for direct application matching
  • 4-wire configuration with 20-gauge wiring
  • Radiused polygon male connector for vehicle-specific connection
  • Threaded mounting with 18.0 mm thread diameter
  • Wiring harness length: 21.65 in.; overall length: 24.60 in.
  • Walker Products Aftermarket engine management sensor line

Product Details

Walker Products Aftermarket focuses on engine management and oxygen/air-fuel sensors developed as OE-style replacements for worldwide vehicle coverage. Part number 350-341018 is built for the specified fitment position and is intended to restore the sensor feedback needed by the ECU on downstream applications. This part number is listed for BMW i8, BMW X1, BMW X2, BMW 220i, and Mini Cooper, Mini Cooper Clubman, Mini Cooper Countryman applications where the cataloged downstream position applies.

For shoppers searching for a downstream oxygen sensor for BMW X2, a BMW i8 downstream sensor replacement, or a Mini Cooper Countryman oxygen sensor, 350-341018 provides the application-specific fitment and connector style required by the vehicle. The heated design supports faster sensor operation after startup, while the threaded mounting and vehicle-matched harness layout help simplify replacement on the correct exhaust location.

What It Helps Address

  • Check engine light related to downstream oxygen sensor faults
  • Poor fuel economy caused by inaccurate exhaust feedback
  • Elevated exhaust emissions from a failing sensor
  • Rough engine operation tied to incorrect ECU input
  • Stored fault codes in the ECU for the affected sensor circuit

Installation Notes and Tips

Confirm the vehicle’s downstream sensor location before ordering, since this part is cataloged for specific BMW and Mini applications only. Inspect the sensor wiring harness and connector for heat damage, abrasion, or corrosion before installation. Verify thread size, connector shape, and harness routing against the original sensor to ensure proper fitment on BMW 220i, BMW X1, BMW X2, BMW i8, and Mini Cooper models.

Quality Assurance

Walker Products has supplied engine management and fuel system components since 1946 and operates with Automotive ISO9001/TS 16949 certification. The 350-341018 oxygen sensor is manufactured for the specified application and position to provide the diagnostic feedback expected by the ECU.

Related reading

This part fits 87 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelSubmodelDrive TypeLitersCylindersFuel TypePositionNotes
2024MiniCooper Countryman—AWD1.5LL3—DownstreamOE Replacement
2023BMWX2——2.0LL4—DownstreamOE Replacement
2023MiniCooper Countryman—AWD1.5LL3—DownstreamOE Replacement
2022BMWX2——2.0LL4—DownstreamOE Replacement
2022MiniCooper Countryman—AWD1.5LL3—DownstreamOE Replacement
2021BMWX2——2.0LL4—DownstreamOE Replacement
2021MiniCooper——1.5LL3—DownstreamOE Replacement
2021MiniCooper Countryman—AWD1.5LL3—DownstreamOE Replacement
2020BMWi8——1.5LL3ELECTRIC/GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2020BMWX2——2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2020MiniCooperS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2020MiniCooperJohn Cooper Works—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2020MiniCooperBase—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2020MiniCooper ClubmanS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2020MiniCooper ClubmanS ALL4—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2020MiniCooper CountrymanS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2020MiniCooper CountrymanS ALL4—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2020MiniCooper CountrymanJohn Cooper Works ALL4—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2020MiniCooper CountrymanS E ALL4—1.5LL3ELECTRIC/GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2020MiniCooper CountrymanBase—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2020MiniCooper CountrymanALL4—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019BMWi8——1.5LL3ELECTRIC/GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019BMWX1——2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019BMWX2——2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019MiniCooperS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019MiniCooperJohn Cooper Works—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019MiniCooperBase—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019MiniCooper ClubmanS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019MiniCooper ClubmanS ALL4—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019MiniCooper ClubmanJohn Cooper Works ALL4—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019MiniCooper ClubmanBase—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019MiniCooper ClubmanALL4—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019MiniCooper CountrymanS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019MiniCooper CountrymanS ALL4—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019MiniCooper CountrymanJohn Cooper Works ALL4—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019MiniCooper CountrymanS E ALL4—1.5LL3ELECTRIC/GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019MiniCooper CountrymanBase—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2019MiniCooper CountrymanALL4—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018BMW220i——2.0LL4—DownstreamEngine Designation : B48; OE Replacement
2018BMWi8——1.5LL3—DownstreamOE Replacement
2018BMWX1——2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018BMWX2——2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018MiniCooperS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018MiniCooperJohn Cooper Works—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018MiniCooperBase—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018MiniCooper ClubmanS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018MiniCooper ClubmanS ALL4—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018MiniCooper ClubmanJohn Cooper Works ALL4—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018MiniCooper ClubmanBase—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018MiniCooper ClubmanALL4—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018MiniCooper CountrymanS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018MiniCooper CountrymanS ALL4—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018MiniCooper CountrymanJohn Cooper Works ALL4—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018MiniCooper CountrymanS E ALL4—1.5LL3ELECTRIC/GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018MiniCooper CountrymanBase—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2018MiniCooper CountrymanALL4—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017BMW220i——2.0LL4—DownstreamOE Replacement
2017BMWi8——1.5LL3ELECTRIC/GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017BMWX1——2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017MiniCooperS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017MiniCooperJohn Cooper Works—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017MiniCooper——2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017MiniCooperBase—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017MiniCooper ClubmanS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017MiniCooper ClubmanS ALL4—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017MiniCooper ClubmanJohn Cooper Works ALL4—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017MiniCooper Clubman——2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017MiniCooper ClubmanBase—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017MiniCooper ClubmanALL4—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017MiniCooper CountrymanS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017MiniCooper CountrymanS ALL4—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017MiniCooper CountrymanBase—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2017MiniCooper CountrymanALL4—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2016BMW220i——2.0LL4—DownstreamEngine Designation : B48; OE Replacement
2016BMWi8——1.5LL3—DownstreamOE Replacement
2016BMWX1——2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2016MiniCooperS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2016MiniCooperJohn Cooper Works—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2016MiniCooperBase—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2016MiniCooper ClubmanS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2016MiniCooper ClubmanBase—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2015BMWi8——1.5LL3—DownstreamOE Replacement
2015MiniCooperS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2015MiniCooperJohn Cooper Works—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2015MiniCooperBase—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2014MiniCooperS—2.0LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2014MiniCooperBase—1.5LL3GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket