Bosch 18207 Oxygen Sensor - Upstream

Bosch Wideband O2 Sensor for Toyota and Scion

Bosch Validated Oxygen Sensor 18207 is a direct-fit wideband air-fuel ratio sensor for select Toyota and Scion applications. It provides the ECU with continuous, high-resolution AFR data for precise mixture control, including upstream monitoring on the 2016 Scion iA and 2016-2018 Toyota Yaris and 2017-2018 Toyota Yaris iA.

Key Features

• Wide-band sensor type for continuous air-fuel ratio measurement across the full lambda range
• Direct-fit oxygen sensor with specific fitment and threaded mounting
• Heated design for faster sensor warm-up and stable operation
• 5-wire harness with 6 terminals and a rectangle male connector
• 18 mm thread diameter, 22 mm hex size, and steel finish
• 18.9 in wiring harness length and 21.3 in sealing surface to connector end
• Bosch Validated Oxygen Sensor line built on Bosch OE development experience

Product Details

Bosch 18207 is engineered as a standard replacement wideband O2 sensor for upstream locations where accurate air-fuel feedback is critical. Bosch pioneered the planar pump-cell wideband design used in modern engine management, and this sensor reflects that OE-focused approach with fast light-off, controlled heater performance, and durable ceramic construction. For drivers searching for a Toyota Yaris upstream oxygen sensor or a Bosch 18207 replacement for Scion iA and Toyota Yaris iA, this part delivers the detailed signal needed for precise fuel control and emissions monitoring.

This part cross-references 89467WB003 for the same application.

Common Issues This Sensor May Address

• Check engine light related to upstream oxygen sensor performance
• Incorrect air-fuel ratio readings from a worn wideband sensor
• Rough idle or inconsistent fuel control caused by slow sensor response
• Reduced fuel economy from inaccurate exhaust feedback
• Emissions test failures tied to faulty AFR monitoring

Installation Notes and Tips

Install Bosch 18207 in the upstream position only on confirmed applications. Verify connector shape, terminal count, thread size, and harness length before installation. Because this is a direct-fit sensor, use the existing vehicle connector and route the harness away from heat sources and moving components. Always confirm the vehicle’s exact year, make, model, and engine configuration against the fitment data before replacement.

Quality Assurance

Bosch draws on more than five decades of OE sensor development, and the Bosch Validated Oxygen Sensor line is built to meet the demands of modern engine management systems. Bosch 18207 is manufactured as a durable, accurate replacement for select Toyota and Scion upstream applications.