Bosch 13445 Oxygen Sensor - Downstream or Upstream

Bosch Actual OE Oxygen Sensor for Subaru

Bosch 13445 is a narrow-band heated oxygen sensor built for precise air-fuel-ratio feedback to the ECU. It supports stable combustion control and emissions management for Subaru Legacy and Subaru Impreza applications with confirmed upstream and downstream fitment.

Key Features

• Actual OE Oxygen Sensor from Bosch
• Narrow-band heated O2 sensor for closed-loop fuel control
• Specific fit design with threaded mounting
• Square female connector with 4 terminals
• 3-wire harness with included wiring harness
• Metal housing with high-temperature-resistant construction
• 22 mm hex size and 18 mm thread diameter
• Wiring harness length: 14.8 in; overall length: 18.5 in

Product Details

Bosch 13445 uses a switching-type narrow-band design that measures oxygen content in the exhaust stream and sends accurate feedback to the engine control unit. Bosch developed this sensor line from its OE oxygen sensor experience, including faster light-off and improved lambda accuracy through planar narrowband technology. For Subaru Legacy and Subaru Impreza models, this sensor supports consistent fuel-trim control in both upstream and downstream locations. Bosch 13445 is a direct-fit replacement for vehicles that require a threaded, heated oxygen sensor with a square connector and female terminals.

This part cross-references Subaru 22690AA220 for the same application.

Fitment

• Fits 1995 Subaru Legacy, upstream.
• Fits 1995-1998 Subaru Legacy, downstream.
• Fits 1995-1997 Subaru Impreza, upstream.
• Fits 1995-1997 Subaru Impreza, downstream.

Common Issues This Sensor Can Address

• Check engine light related to oxygen sensor performance
• Unstable air-fuel mixture feedback at the ECU
• Delayed closed-loop operation after startup
• Poor emissions control from a worn narrow-band sensor
• Incorrect fuel-trim readings on Subaru Legacy or Subaru Impreza

Installation Notes

Confirm the sensor position, connector shape, terminal count, and thread size before installation. This Bosch 13445 oxygen sensor is a specific-fit part, so match the upstream or downstream location listed for your Subaru Legacy or Subaru Impreza. Inspect the exhaust bung threads and wiring routing before tightening the threaded sensor into place.

Quality Assurance

Bosch backs this oxygen sensor with more than five decades of OE development in emissions and engine-management sensing. The design uses advanced ceramic elements, optimized heater control, and heat-resistant materials to maintain consistent signal quality under thermal and vibration load.