Bosch 16009 Oxygen Sensor - Downstream or Downstream Left

Bosch Actual OE Oxygen Sensor 16009

Bosch 16009 is a narrow-band heated oxygen sensor built for downstream monitoring on select Mercedes-Benz and INFINITI applications. It uses a threaded, specific-fit design with a 4-wire harness and pin terminals to deliver accurate air-fuel-ratio feedback to the ECU for stable closed-loop control.

The Bosch Actual OE Oxygen Sensor line draws on Bosch’s long OE development history, including narrowband planar sensor designs that improve light-off speed, lambda accuracy, and closed-loop response. For drivers servicing a Mercedes-Benz C300, GLC300, E300, or an INFINITI Q50, this part number 16009 provides an OE-style replacement built around the original equipment application.

Key Features

• Specific-fit downstream oxygen sensor for select Mercedes-Benz and INFINITI vehicles
• Narrow-band heated sensor design for precise exhaust feedback
• 4-wire configuration with rectangular female connector
• Threaded mounting with 18 mm thread size and 22 mm hex
• Wiring harness included with 16.4 in harness length
• Metal housing and high-temperature-resistant construction for demanding exhaust conditions
• Actual OE Oxygen Sensor line engineered around OE-proven sensor technology

Detailed Description

Bosch 16009 is a downstream oxygen sensor that measures exhaust oxygen content and sends the signal to the engine control unit for fuel-trim management. Its narrow-band heated design supports quicker closed-loop operation after startup, while the ceramic sensing element and controlled heater help maintain signal stability across changing thermal loads. This makes it a direct replacement choice for vehicles that rely on accurate downstream monitoring to maintain emissions performance and drivability. Bosch’s Actual OE Oxygen Sensor line is built from the company’s original OE sensor development work, including the transition from early thimble-style sensors to later planar narrowband designs. That OE background is reflected in the sensor’s specific-fit connector, threaded mounting, and application-matched harness length. This part number 16009 is listed for models such as Mercedes-Benz C300, GLC300, E300, and INFINITI Q50, with downstream placement specified by application.

This part cross-references 226A04GD0B and 0075426418 for the same application.

What It Helps Address

• Check engine light related to downstream oxygen sensor performance
• Incorrect air-fuel ratio feedback to the ECU
• Slow sensor response after warm-up
• Emissions test failures tied to oxygen sensor faults
• Rough fuel-trim control caused by a worn or contaminated sensor

Installation Notes and Tips

Verify the connector shape, wire count, thread size, and downstream position before installation. Bosch 16009 uses a threaded 18 mm sensor body with a 22 mm hex, so the correct oxygen sensor socket or wrench is recommended. Confirm the vehicle application by year, make, model, and sensor location before replacing the original unit. For listed applications, this part is used on downstream positions including Mercedes-Benz Maybach S680, GLC350e, SLC300, E300, GLC300, C300, C350e, SLK300, and INFINITI Q50, QX50, and Q60.

Quality Assurance

Bosch backs this oxygen sensor with more than five decades of OE sensor development and aftermarket supply experience. The Actual OE Oxygen Sensor line is built to OE-proven standards for signal accuracy, heater control, and durability under heat and vibration.

Compatible Vehicles

• Fits 2022-2025 Mercedes-Benz Maybach S680, downstream left
• Fits 2018-2020 Mercedes-Benz GLC350e, downstream
• Fits 2017-2020 Mercedes-Benz SLC300, downstream
• Fits 2016-2019 INFINITI Q50, downstream
• Fits 2019 INFINITI QX50, downstream
• Fits 2017-2019 Mercedes-Benz E300, downstream
• Fits 2016-2019 Mercedes-Benz GLC300, downstream
• Fits 2017-2018 INFINITI Q60, downstream
• Fits 2015-2018 Mercedes-Benz C300, downstream
• Fits 2016-2018 Mercedes-Benz C350e, downstream
• Fits 2016 Mercedes-Benz SLK300, downstream