Bosch 15769 Oxygen Sensor - Downstream

Bosch OE Oxygen Sensor for Downstream Use

Bosch 15769 is an Actual OE Oxygen Sensor built as a narrow-band heated replacement for downstream applications. It measures exhaust oxygen content and sends precise air-fuel-ratio data to the ECU, helping maintain stable combustion control and lower emissions in supported Nissan, Mercury, and related applications.

Key Features

• Actual OE Oxygen Sensor from Bosch Actual OE Oxygen Sensor line
• Narrow-band heated sensor type for closed-loop fuel control
• Specific fit design with threaded mounting
• 4-wire harness with square connector and blade terminals
• Metal housing with high-temperature-resistant construction
• 22 mm hex size and 18 mm thread diameter
• Wiring harness included; harness length measures 47.3 in
• Overall length measures 51 in; sealing surface to connector end measures 49.8 in

Detailed Description

Bosch 15769 uses a switching-type narrow-band design to provide the ECU with accurate oxygen-sensor feedback during downstream exhaust monitoring. Bosch’s OE development history includes early thimble-style sensors and later planar narrowband designs, and this replacement reflects that experience with faster light-off characteristics, improved lambda accuracy, and quicker closed-loop response. For drivers searching for a downstream oxygen sensor for 1998-2000 Nissan Frontier, 1999-2000 Nissan Quest with California Emission System, or 1999-2002 Mercury Villager, Bosch 15769 delivers the OE-style fit and signal behavior expected in these applications. This part cross-references Monroe Shocks & Struts (e.g., 226A03S571, 226A04M221) for the same application.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio feedback to the ECU
• Rough idle or unstable combustion control from a failing downstream sensor
• Emissions test failures tied to sensor response issues
• Slow sensor switching or degraded closed-loop operation

Installation Notes and Tips

Install Bosch 15769 in the threaded downstream location specified by the vehicle application. Verify the 4-wire connector, square connector shape, and 18 mm thread size before installation. Use the correct 22 mm oxygen sensor socket and route the harness away from heat and vibration sources. Confirm the vehicle’s emission configuration, since some Nissan Frontier and Quest applications are listed with California Emission System notes.

Quality Assurance

Bosch supplies this oxygen sensor from its OE development background, using ceramic sensing elements, controlled heater operation, and heat-resistant materials for consistent signal output under demanding exhaust temperatures and vibration.