Bosch 13338 Oxygen Sensor - Downstream

Bosch Validated Oxygen Sensor 13338

Bosch Validated Oxygen Sensor 13338 is a specific-fit, narrow-band heated O2 sensor for downstream applications on select Lexus RX300 and Toyota Highlander models. It provides direct air-fuel-ratio feedback to the ECU for stable closed-loop control and emissions monitoring.

Key Features

• Specific-fit oxygen sensor for direct replacement applications
• Narrow-band heated design for faster light-off and quicker closed-loop operation
• 4-wire configuration with rectangular male connector
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• Wiring harness included with 16.3 in harness length
• Metal housing with high-temperature-resistant construction
• Standard replacement grade for downstream sensor service

Product Details

Bosch 13338 is built around Bosch Validated Oxygen Sensor engineering, drawing on Bosch narrowband sensor development for accurate lambda feedback under changing load and temperature conditions. The heated sensor element and optimized heater control help the sensor reach operating temperature quickly, while the ceramic sensing element supports consistent signal output in demanding exhaust environments. This Bosch oxygen sensor is a direct-fit replacement for 1999-2003 Lexus RX300 downstream and 2001-2003 Toyota Highlander downstream applications. If you are replacing a downstream O2 sensor on a Lexus RX300 or Toyota Highlander, Bosch 13338 provides the OE-style fit and signal behavior expected for emissions and fuel-control service. This part cross-references 8946549075 for the same application.

Common Issues This Part May Resolve

• Check engine light related to downstream oxygen sensor performance
• Slow or unstable oxygen sensor signal response
• Incorrect air-fuel feedback affecting closed-loop operation
• Emissions test failure caused by a worn O2 sensor
• Rough fuel-control behavior from an aging narrow-band sensor

Installation Notes and Tips

Verify the downstream sensor location before ordering and confirm the 18 mm thread size, 4-wire connector, and rectangular plug style match the original unit. Inspect the exhaust bung threads and connector condition before installation, and route the harness away from heat sources and moving components. Use proper oxygen sensor service tools to avoid damaging the sensor body or exhaust threads.

Quality Assurance

Bosch has decades of OE oxygen sensor development behind this product line, and the Validated Oxygen Sensor range is built to deliver OE-proven fit, signal accuracy, and durability for aftermarket replacement.