Bosch 12105 Oxygen Sensor - Downstream or Upstream

Bosch Oxygen Sensor for Toyota Applications

Bosch 12105 is a narrow-band, non-heated oxygen sensor built for specific-fit replacement in select Toyota vehicles. It provides the ECU with air-fuel-ratio feedback needed for stable combustion control and emissions monitoring.

Compatible With 1996 Toyota Camry upstream, 1996-1997 Toyota RAV4 downstream, 1996-1998 Toyota Celica upstream, and 1999 Toyota Celica downstream. Bosch Engineered Oxygen Sensor 12105 is a direct-fit option for drivers replacing a worn sensor on these applications.

Key Features

• Specific-fit oxygen sensor for select Toyota models
• Narrow-band, non-heated sensor type
• Blade terminals with a rectangular male connector
• Wiring harness included for the listed application
• Flange mounting style with 18 mm thread size
• Steel finish and metal housing for underbody service conditions
• 10.1 in wiring harness length and 13.8 in overall length
• 22 mm hex size for service removal

Product Details

Bosch Engineered Oxygen Sensor 12105 reflects Bosch’s long OE development history in oxygen sensing, beginning with early sensor designs and later narrowband planar technology. This sensor uses advanced ceramic elements and controlled heater-related engineering principles from Bosch’s broader oxygen sensor line, while this specific unit is a non-heated narrow-band design for the listed Toyota fitments. It is intended to deliver accurate exhaust feedback to the ECU so the engine can maintain proper fuel control during normal operation. This part cross-references Monroe Shocks & Struts (e.g., 172286, 182286) for the same application.

Common Issues This Sensor Can Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio feedback to the ECU
• Rough idle caused by degraded exhaust sensor readings
• Failed emissions inspection tied to sensor response problems
• Reduced fuel control accuracy on aging Toyota exhaust systems

Installation Notes

Verify the upstream or downstream location before ordering, since Bosch 12105 is listed for specific positions only. Confirm the 18 mm thread size, 22 mm hex size, and rectangular male connector match the original sensor before installation. Inspect the harness routing and connector condition during replacement, and clear diagnostic trouble codes after the repair if required by the vehicle.

Quality Assurance

Bosch supplies oxygen sensors backed by more than five decades of OE development and aftermarket application experience. Bosch Engineered Oxygen Sensor 12105 is built to OE-proven standards for the listed Toyota Camry, RAV4, and Celica applications.