Bosch 13891 Oxygen Sensor - Downstream

Bosch OE Oxygen Sensor for Mitsubishi Galant

Bosch 13891 is a narrow-band heated oxygen sensor built for precise air-fuel-ratio feedback to the ECU. It is a specific-fit replacement for the downstream position on 1995-1998 Mitsubishi Galant models with California Emission System equipment.

The Bosch Actual OE Oxygen Sensor line draws on Bosch’s long OE development history, including narrowband planar sensor designs that improve warm-up response, lambda accuracy, and closed-loop operation. Bosch 13891 uses a threaded metal housing, integrated wiring harness, and a 4-wire configuration for stable signal delivery in demanding exhaust conditions.

Key Features

• Specific-fit downstream oxygen sensor for 1995-1998 Mitsubishi Galant
• Heated narrow-band sensor for faster closed-loop operation
• 4-wire design with round male connector and female terminals
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• Integrated wiring harness with 17.7 in. sealing-surface-to-connector length
• Standard replacement grade for OE-style service applications
• Bosch 13891 part number for direct catalog lookup

Detailed Description

Bosch 13891 is an Actual OE Oxygen Sensor engineered for downstream exhaust monitoring on the Mitsubishi Galant. It measures oxygen content in the exhaust stream and sends accurate feedback to the engine control unit, helping maintain stable combustion control and emissions performance. For drivers searching for a downstream oxygen sensor for 1995-1998 Mitsubishi Galant California Emission System applications, this Bosch replacement provides the correct fitment and sensor type.

This Bosch oxygen sensor uses a narrow-band heated design with a threaded steel finish and metal housing for durability in high-temperature exhaust locations. The 4-wire layout, round connector shape, and included harness support straightforward replacement of the original sensor configuration. Bosch 13891 is also referenced under MD335028 for the same application.

What It Helps Address

• Faulty oxygen sensor signal causing unstable fuel control
• Check engine light related to downstream O2 sensor performance
• Excessive emissions from inaccurate exhaust oxygen readings
• Rough combustion control after sensor aging or thermal wear
• Delayed closed-loop response from a worn heated narrow-band sensor

Installation Notes and Tips

Fits 1995-1998 Mitsubishi Galant, downstream, with California Emission System. Confirm the threaded 18 mm sensor opening, 4-wire connector layout, and downstream location before installation. Use the correct oxygen sensor socket for the 22 mm hex size and inspect the harness routing so the connector reaches the factory mounting point without strain.

Quality Assurance

Bosch backs this Actual OE Oxygen Sensor line with more than five decades of OE development and aftermarket supply experience. Bosch 13891 is built to OE-style standards for accurate signal output, consistent heater control, and dependable service in demanding exhaust environments.