Bosch 13524 Oxygen Sensor - Upstream

Bosch Actual OE Oxygen Sensor 13524

Bosch 13524 is a narrow-band heated oxygen sensor built for precise air-fuel ratio feedback to the ECU. It supports stable combustion control and emissions management for the 1996-1997 Audi A4 and 1996-1997 Audi A4 Quattro, upstream applications.

Key Features

• Actual OE Oxygen Sensor from Bosch
• Narrow-band heated O2 sensor for closed-loop fuel control
• Specific-fit design with wiring harness included
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• Oblong male connector with 3-wire configuration
• Metal housing for high-temperature and vibration resistance
• Wiring harness length: 15.2 in; overall length: 18.9 in

Detailed Description

Bosch 13524 uses a switching-type sensing element to report exhaust oxygen content to the engine control unit, helping the system maintain the correct air-fuel mixture during warm-up and normal driving. Bosch developed this oxygen sensor line from its original OE sensor designs and later planar narrowband technology, focusing on faster light-off, accurate lambda feedback, and quicker closed-loop response. This part cross-references 078906265D for the same application.

Compatible with 1996-1997 Audi A4, upstream, and 1996-1997 Audi A4 Quattro, upstream, Bosch 13524 is a direct-fit replacement for vehicles that require a narrow-band heated sensor in the listed position. The threaded metal body, blade terminals, and integrated harness support a factory-style connection and installation layout.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio readings at the ECU
• Rough idle or unstable fuel control after sensor aging
• Slow closed-loop operation during warm-up
• Elevated emissions from a worn upstream sensor

Installation Notes and Tips

Verify the upstream location and connector style before installation. Use the correct 18 mm oxygen sensor socket or 22 mm hex tool, and inspect the harness routing so the lead is kept away from exhaust heat and moving components. Confirm thread size and connector match the original sensor before replacement.

Quality Assurance

Bosch backs this oxygen sensor with more than five decades of OE development and supplies aftermarket parts built to OE-proven standards used by vehicle manufacturers.