Bosch 13038 Oxygen Sensor - Upstream

Bosch Actual OE Oxygen Sensor 13038

Bosch 13038 is a specific-fit, narrow-band heated oxygen sensor for precise air-fuel ratio feedback to the ECU. It is built for stable combustion control and emissions monitoring in compatible BMW applications, including 1987-1988 BMW 325is, 1988 BMW 325i, and 1988 BMW 528e upstream positions.

Key Features

• Actual OE Oxygen Sensor from Bosch
• Narrow-band heated oxygen sensor type for closed-loop fuel control
• Specific fit with threaded mounting and 18 mm thread size
• 4-wire design with 4 terminals and round connector
• Wiring harness included; harness length measures 21.5 in
• Steel finish with metal housing for high-temperature service
• 22 mm hex size for service removal and installation

Product Details

As part of Bosch’s Actual OE Oxygen Sensor line, part number 13038 reflects Bosch’s long-running OE development in switching-type O2 sensor technology. Bosch uses ceramic sensing elements, controlled heater operation, and heat-resistant materials to deliver fast sensor response, accurate lambda feedback, and consistent operation under thermal and vibration load. This makes Bosch 13038 a direct replacement choice for BMW 325i, BMW 325is, and BMW 528e upstream oxygen sensor service where precise mixture control is required.

This part cross-references BMW OE numbers 11781714772 and 11781716114 for the same application.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Rich or lean air-fuel mixture readings
• Slow closed-loop fuel control response
• Inconsistent idle quality tied to exhaust feedback issues
• Emissions test failures caused by a worn upstream sensor

Installation Notes

Install Bosch 13038 in the upstream location specified for the vehicle application. Confirm connector shape, wire count, thread diameter, and harness routing before installation. The sensor uses an 18 mm threaded mount and a round connector with blade-pin terminals, so matching the original configuration is important for proper fitment on the BMW 325i, BMW 325is, and BMW 528e.

Quality Assurance

Bosch has more than five decades of OE oxygen sensor development behind this Actual OE line. The sensor is engineered to meet the demands of factory-style fuel control and emissions monitoring in compatible BMW applications.