Bosch 13394 Oxygen Sensor - Downstream

Bosch Actual OE Oxygen Sensor for Hyundai

Bosch Part Number 13394 is an Actual OE Oxygen Sensor built for downstream use on select Hyundai applications. It uses a narrow-band heated design with a threaded mount, 4-wire harness, and OE-style connector layout to deliver accurate air-fuel ratio feedback to the ECU.

For drivers searching for a downstream oxygen sensor for 1997-2001 Hyundai Accent, Elantra, or Tiburon, Bosch 13394 provides the OE-proven fit and signal behavior expected from a standard replacement sensor.

Key Features

• Actual OE Oxygen Sensor from Bosch
• Narrow-band heated sensor type for closed-loop fuel control
• Specific fit with threaded mounting
• 4-wire harness with rectangular male connector
• Wiring harness included for direct replacement use
• 18 mm thread diameter and 22 mm hex size
• Steel-finish metal housing for high-temperature service
• Bosch Part Number 13394

Product Details

Bosch’s Actual OE Oxygen Sensor line is based on decades of original equipment development, including Bosch’s early thimble sensor designs and later planar narrowband technology. This sensor measures exhaust oxygen content and sends precise feedback to the ECU so the engine can maintain stable combustion control and emissions performance across changing operating conditions. Bosch uses ceramic sensing elements, controlled heater operation, and heat-resistant materials to support consistent output under thermal and vibration load. Bosch 13394 is a direct-fit downstream sensor for select Hyundai models, including 1997-1998 Hyundai Accent, 1998-2000 Hyundai Elantra, and 1998-2001 Hyundai Tiburon. This part cross-references Hyundai OE numbers 3921022051 and 3921023036 for the same application.

Common Issues This Sensor Can Address

• Check engine light related to oxygen sensor performance
• Delayed or unstable closed-loop fuel control
• Incorrect air-fuel ratio feedback to the ECU
• Emissions test failure tied to downstream sensor output
• Rough combustion control caused by a worn narrow-band sensor

Installation Notes and Tips

Verify the downstream location and connector style before installation. This sensor uses a threaded 18 mm mount, a 4-wire configuration, and a rectangular male connector with a 13.6 in wiring harness length. Confirm vehicle-specific fitment for 1997-2001 Hyundai Accent, Elantra, and Tiburon applications, including California and non-California emission system listings where noted. Inspect the exhaust bung threads and connector routing before tightening the sensor into place.

Quality Assurance

Bosch backs this oxygen sensor with more than five decades of OE development experience and supplies it as an OE-proven replacement part for aftermarket service.