Bosch 13425 Oxygen Sensor - Upstream or Upstream Right

Bosch Oxygen Sensor for OE-Style Emissions Control

Bosch Part Number 13425 is a narrow-band heated oxygen sensor built for precise air-fuel ratio feedback to the ECU. It is a specific-fit replacement with a 4-wire, threaded design for stable closed-loop operation and consistent emissions control.

Built under the Bosch Engineered Oxygen Sensor line, this sensor reflects Bosch’s long OE development history in oxygen sensing technology. The design uses advanced ceramic elements, optimized heater control, and high-temperature-resistant materials to maintain accurate signal response under heat and vibration.

Key Features

• Specific-fit oxygen sensor for direct application matching
• Narrow-band heated sensor type for standard replacement use
• 4-wire configuration with square connector and male terminals
• Threaded mounting with 18 mm thread size and 22 mm hex size
• Wiring harness included with 36.4 in harness length
• Steel finish with metal housing for underbody durability
• Bosch Part Number 13425 for catalog and cross-reference use

Detailed Description

Bosch 13425 is an upstream oxygen sensor used to monitor exhaust oxygen content and send a switching signal to the engine control unit. That feedback helps the ECU maintain the correct air-fuel mixture during closed-loop operation, which supports smoother combustion and lower emissions. This Bosch Engineered Oxygen Sensor is a direct replacement choice for Mitsubishi Eclipse, Mitsubishi Montero Sport, Mitsubishi Diamante, and Dodge Stealth applications listed below.

Fits 1995-1999 Mitsubishi Eclipse, upstream. Fits 1997-1999 Mitsubishi Montero Sport, upstream with California Emission System. Fits 1994-1996 Mitsubishi Diamante, upstream right with California Emission System. Fits 1994 Dodge Stealth, upstream right, optional with California Emission System. This part cross-references Mitsubishi OE numbers MD305146 and MD313819 for the same application.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Rough idle caused by inaccurate air-fuel feedback
• Rich or lean running conditions during closed-loop operation
• Elevated exhaust emissions from a slow or aging sensor
• Delayed sensor response after warm-up

Installation Notes and Tips

Confirm the vehicle position before ordering, since this part is listed for upstream and upstream right locations depending on application. Verify the 4-wire connector, square connector shape, and 18 mm threaded mounting before installation. Because this is a heated narrow-band sensor, proper connector routing and secure harness placement are important to avoid heat damage and vibration wear.

Quality Assurance

Bosch has more than five decades of OE oxygen sensor development behind this replacement part. The Bosch Engineered Oxygen Sensor line is built to OE-style standards for accurate signal output, durable heater performance, and dependable operation in demanding thermal conditions.