Bosch 16274 Oxygen Sensor - Upstream or Upstream Left

Bosch Actual OE Oxygen Sensor 16274

Bosch 16274 is a specific-fit, narrow-band heated oxygen sensor for upstream applications on select Mercedes-Benz models. It delivers air-fuel-ratio feedback to the ECU for stable closed-loop control and emissions management, with OE-style construction for consistent signal response.

Key Features

• Specific-fit Bosch Actual OE Oxygen Sensor for direct application matching
• Narrow-band heated sensor with 4-wire configuration
• Round female connector with pin terminals and included wiring harness
• Threaded mounting, 18 mm thread diameter, 22 mm hex size
• Steel finish with metal housing for high-temperature service
• Wiring harness length: 15.9 in; overall length: 19.3 in
• Cross-reference: Mercedes-Benz 0015405117

Product Line Details

Bosch Actual OE Oxygen Sensor parts are built from Bosch’s long-running OE oxygen sensor development. This line uses ceramic sensing elements, controlled heater operation, and heat-resistant materials to support accurate lambda measurement and fast closed-loop response across changing engine loads and temperatures.

Detailed Description

Bosch part number 16274 is an upstream narrow-band oxygen sensor for Mercedes-Benz CL500, CL55 AMG, S350, S430, S500, S55 AMG, E320, E430, and E55 AMG applications listed below. It is also a direct replacement for Mercedes-Benz 0015405117. The sensor’s heated design helps it reach operating temperature quickly, while the OE-style signal output supports precise fuel control and emissions monitoring.

Fits 2001-2006 Mercedes-Benz CL500, Upstream. Fits 2001-2006 Mercedes-Benz CL55 AMG, Upstream. Fits 2006 Mercedes-Benz S350, Upstream. Fits 2001-2006 Mercedes-Benz S430, Upstream. Fits 2001-2006 Mercedes-Benz S500, Upstream. Fits 2001-2006 Mercedes-Benz S55 AMG, Upstream. Fits 2001-2003 Mercedes-Benz E320, Upstream Left. Fits 2001-2002 Mercedes-Benz E430, Upstream Left. Fits 2000-2002 Mercedes-Benz E55 AMG, Upstream Left.

Common Issues This Sensor Addresses

• Fault codes related to oxygen sensor response or signal range
• Rough idle or unstable air-fuel control during closed-loop operation
• Increased emissions from inaccurate exhaust oxygen measurement
• Delayed sensor warm-up after cold starts
• Fuel trim problems caused by a worn upstream sensor

Installation Notes and Tips

Confirm the upstream position and connector style before installation. This sensor uses an 18 mm threaded mount, a round female connector, and a 4-wire harness layout. Inspect the exhaust bung threads and wiring routing before tightening the sensor to avoid connector strain or exhaust leaks.

Quality Assurance

Bosch backs this oxygen sensor with more than five decades of OE development experience. The design reflects Bosch’s original oxygen sensor engineering and later planar narrowband advancements, with a focus on accurate measurement, fast light-off, and durable operation in demanding thermal and vibration conditions.