Bosch 18168 Oxygen Sensor - Downstream Left

Bosch Validated Oxygen Sensor for Lexus and Toyota

Bosch Part Number 18168 is a specific-fit, narrow-band heated oxygen sensor for downstream left applications on select Lexus RX and Toyota Sienna and Highlander models. It provides precise air-fuel-ratio feedback to the ECU, helping maintain stable combustion control and lower emissions across changing driving conditions.

The Bosch Validated Oxygen Sensor line builds on Bosch OE development in oxygen sensing, using durable ceramic elements, optimized heater control, and high-temperature-resistant materials for consistent signal performance in demanding exhaust environments.

Key Features

• Specific-fit Bosch oxygen sensor for direct application matching
• Narrow-band heated sensor design for closed-loop fuel control
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• 4-wire configuration with square male connector and blade terminals
• Wiring harness included; harness length measures 10.2 in.
• Standard replacement grade for OE-style service work
• Metal housing with threaded mounting for exhaust installation

Detailed Product Overview

Bosch 18168 is engineered as a downstream left oxygen sensor for vehicles that rely on accurate exhaust feedback to manage fuel delivery and emissions performance. It is a narrow-band heated O2 sensor with a 14 in. overall length, 12.8 in. sealing-surface-to-connector length, and a 4-terminal layout for direct electrical connection. The Bosch Validated Oxygen Sensor platform is backed by more than five decades of OE development, and this part reflects that experience with materials and heater control chosen for stable operation under heat and vibration.

Compatible with 2021-2022 Lexus RX350, 2018-2022 Lexus RX350L, 2021-2022 Lexus RX450h, 2018-2022 Lexus RX450hL, 2020 Lexus RX350, 2016-2018 Lexus RX350, 2016-2020 Lexus RX450h, 2017-2020 Toyota Sienna, 2019 Lexus RX350, and 2017-2019 Toyota Highlander in the downstream left position. This part cross-references 894650E210 for the same application. Bosch Part Number 18168 is a practical OE-style replacement for service on these Lexus RX and Toyota platforms.

What It Helps Address

• Fault codes related to oxygen sensor signal performance
• Rough or unstable fuel mixture control in closed-loop operation
• Elevated emissions from inaccurate exhaust oxygen readings
• Delayed sensor response after warm-up
• Drivability issues tied to degraded downstream O2 feedback

Installation Notes and Tips

Verify the downstream left location, connector shape, wire count, and thread size before installation. The sensor uses an 18 mm thread and a 22 mm hex, so the correct oxygen sensor socket or wrench is recommended. Inspect the harness routing and connector condition during replacement, and confirm the vehicle application against the listed fitment for Lexus RX350, RX350L, RX450h, RX450hL, Toyota Sienna, and Toyota Highlander.

Quality Assurance

Bosch draws on long-term OE oxygen sensor development and validated aftermarket engineering for this part. Bosch Part Number 18168 is built with heated narrow-band sensor technology and high-temperature-resistant construction for consistent service in exhaust-system conditions.