Bosch 18105 Oxygen Sensor - Downstream

Bosch Validated Oxygen Sensor for Downstream Use

Bosch Validated Oxygen Sensor 18105 is a specific-fit, narrow-band heated oxygen sensor built for downstream applications. It provides precise air-fuel-ratio feedback to the ECU for stable combustion control and lower emissions, with OE-developed sensor technology from Bosch.

• Specific-fit oxygen sensor for downstream placement
• Narrow-band heated design for faster closed-loop operation
• 4-wire layout with square male connector and blade terminals
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• Wiring harness included for direct replacement use
• Metal housing for high-temperature and vibration resistance

Bosch Validated Oxygen Sensor Line

The Bosch Validated Oxygen Sensor line draws on Bosch OE development dating back to the original oxygen sensor design introduced in 1976. This product line uses advanced ceramic elements, optimized heater control, and durable high-temperature materials to deliver accurate lambda sensing and consistent signal response across changing engine loads.

Vehicle Fitment

• Fits 2015-2017 Kia K900, downstream
• Fits 2012-2016 Hyundai Genesis, downstream
• Fits 2013-2016 Hyundai Genesis Coupe, downstream

This part cross-references Hyundai/Kia OE number 392103C530 for the same application.

What This Oxygen Sensor Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio readings at the ECU
• Slow closed-loop fuel control response
• Elevated emissions from a worn downstream sensor
• Rough combustion control caused by degraded sensor output

Installation Notes

Confirm downstream location, connector shape, terminal count, and thread size before installation. Use the 18 mm threaded mount and verify the 4-wire harness routing matches the original sensor path. Inspect the exhaust bung and wiring connector for heat damage or corrosion before replacing the sensor.

Quality Assurance

Bosch has more than five decades of OE oxygen sensor development, and this Validated Oxygen Sensor is built to the same type of engineering standards used by vehicle manufacturers. Bosch 18105 is a standard replacement part for the listed Hyundai and Kia applications.