Bosch 15901 Oxygen Sensor - Downstream or Downstream Left

Bosch Oxygen Sensor for Downstream Applications

Bosch Part Number 15901 is a narrow-band heated oxygen sensor built for specific downstream applications. It provides the ECU with accurate air-fuel-ratio feedback to support stable combustion control and lower emissions across a wide range of operating conditions.

Compatible With 2002-2007 Chevrolet Silverado, 2002-2007 GMC Sierra, 2002-2006 Chevrolet Suburban 2500, 2002-2006 GMC Yukon XL 2500, 2007 Pontiac Solstice, and 2007 Saturn Sky applications listed below.

Key Features

• Bosch Engineered Oxygen Sensor line with OE-focused design and calibration
• Narrow-band heated oxygen sensor for downstream use
• Specific-fit replacement with 4-wire, square female connector
• Threaded mounting with 18 mm thread size and 22 mm hex size
• Wiring harness included with 19.1 in harness length
• Metal housing with high-temperature-resistant construction
• Part Number 15901 for direct catalog identification

Product Details

Bosch developed its oxygen sensor technology from early thimble-style designs to later planar narrowband sensors that respond faster and enter closed-loop operation more quickly. This Bosch Engineered Oxygen Sensor uses advanced ceramic elements and optimized heater control to deliver consistent signal output under heat and vibration. For vehicles such as the Chevrolet Silverado 1500 HD, GMC Sierra 2500 HD, and Chevrolet Silverado 3500, the sensor is specified for downstream left or downstream positions depending on application.

This part cross-references Monroe Shocks & Struts (e.g., 19209812) for the same application.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio readings sent to the ECU
• Rough or unstable combustion control during closed-loop operation
• Elevated exhaust emissions from a worn downstream sensor
• Slow sensor response after heat cycling or vibration exposure

Installation Notes and Tips

Verify the connector shape, wire count, and threaded mounting style before installation. This Bosch 15901 sensor is a specific-fit replacement, so match the vehicle position exactly to the catalog listing, including downstream left or downstream applications for the Chevrolet Silverado, GMC Sierra, and related models. Inspect the exhaust bung threads and wiring routing before tightening the sensor to the specified 18 mm thread size.

Quality Assurance

Bosch backs this oxygen sensor with more than five decades of OE development in emission control sensing. The Bosch Engineered Oxygen Sensor line is built to the same OE-informed standards trusted by vehicle manufacturers, with materials selected for thermal durability and consistent signal accuracy.