Bosch 18075 Oxygen Sensor - Downstream

Bosch Validated Oxygen Sensor for Subaru

Bosch Validated Oxygen Sensor 18075 is a specific-fit downstream narrow-band heated O2 sensor built for precise air-fuel-ratio feedback to the ECU. It is engineered for Subaru Legacy, Forester, Crosstrek, Impreza, Outback, and XV Crosstrek applications where accurate closed-loop control and stable emissions performance matter.

Key Features

• Specific-fit replacement for downstream applications
• Narrow-band heated oxygen sensor design
• 4-wire configuration with rectangular male connector
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• Wiring harness included with 12.2 in harness length
• Metal housing with high-temperature-resistant construction
• Bosch Validated Oxygen Sensor line backed by Bosch OE development experience

Product Details

Bosch 18075 uses a switching-type sensing element to report exhaust oxygen content to the engine control unit, helping maintain stable combustion control across changing load and temperature conditions. Bosch’s oxygen sensor development includes early thimble-style designs and later planar narrowband technology, which improved light-off response, lambda accuracy, and closed-loop operation. This downstream sensor is built with advanced ceramic elements and optimized heater control for consistent performance under thermal and vibration stress. This part cross-references Subaru OE numbers 22690AA96A and 22690AA960 for the same application.

What This Sensor Helps Address

• Check engine light related to downstream oxygen sensor faults
• Erratic fuel trim readings from a worn O2 sensor
• Slow sensor response during closed-loop operation
• Emissions test failures tied to oxygen sensor performance
• Rough combustion control caused by inaccurate exhaust feedback

Installation Notes

Compatible With 2013-2019 Subaru Legacy, downstream; 2011-2018 Subaru Forester, downstream; 2016-2017 Subaru Crosstrek, downstream; 2012-2016 Subaru Impreza, downstream; 2013-2015 Subaru Outback, downstream; and 2013-2015 Subaru XV Crosstrek, downstream. Verify connector shape, thread size, and harness routing before installation. Use the correct oxygen sensor socket and follow factory service procedures for removal and torque.

Quality Assurance

Bosch draws on more than five decades of OE oxygen sensor development, and the Validated Oxygen Sensor line is built to OE-proven standards for aftermarket replacement. Bosch 18075 is engineered for durable, accurate operation in demanding exhaust environments.