Bosch 18198 Oxygen Sensor - Upstream

Bosch Wideband O2 Sensor for Upstream Control

Bosch Validated Oxygen Sensor 18198 is a specific-fit, heated wideband air-fuel ratio sensor for precise upstream mixture monitoring. It delivers continuous lambda measurement for accurate fuel control, stable drivability, and lower emissions in the applications listed below.

The Bosch Validated Oxygen Sensor line reflects Bosch OE development in modern engine management. This wideband A/F sensor uses a planar pump-cell design, fast light-off behavior, optimized heater control, and a robust ceramic body to maintain accurate readings during rapid load changes and thermal cycling.

• Wideband oxygen sensor for continuous air-fuel ratio measurement
• Heated design for faster sensor activation
• Specific-fit replacement with 5-wire configuration
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• Female connector and female terminals with included wiring harness
• Overall length: 17.9 in; harness length: 14.4 in
• Standard replacement grade for OE-style service

Vehicle Fitment

• Fits 2021-2025 Lincoln Corsair, Upstream.
• Fits 2019-2024 Ford Edge, Upstream.
• Fits 2022-2023 Lincoln Nautilus, Upstream.
• Fits 2020-2022 Ford Escape, Upstream.
• Fits 2017-2019 Ford Escape, Upstream.

Use Bosch 18198 when replacing an upstream wideband sensor on a Ford Edge, Ford Escape, Lincoln Corsair, or Lincoln Nautilus with the listed model years. This part cross-references Ford/Lincoln OE numbers GJ5Z9F472B and K2GZ9F472B for the same application.

Common Issues This Sensor Can Address

• Fault codes related to air-fuel ratio or oxygen sensor performance
• Rough idle caused by inaccurate upstream mixture feedback
• Reduced fuel economy from poor fuel-trim control
• Delayed sensor response during cold start or load changes
• Emissions test failures tied to incorrect mixture readings

Installation Notes

Install this sensor in the upstream position only for the listed applications. Verify the 5-wire connector style, 18 mm thread size, and oblong female connector before installation. Because this is a specific-fit sensor with an included harness, match the connector routing and sensor location to the original part on the vehicle.

Quality Assurance

Bosch has more than five decades of OE sensor development behind this oxygen sensor line, and the design reflects the same engineering approach used in modern factory engine-management systems. Bosch 18198 is built as a standard replacement part for accurate upstream air-fuel ratio control.