Walker 242-1139 Ignition Knock (Detonation) Sensor

Walker Products 242-1139 Knock Sensor

Walker Products 242-1139 is an ignition knock sensor for select Audi and Volkswagen applications. It is built for vehicles that need accurate detonation detection to help the engine control system adjust timing under load.

Key Features

• Ignition knock (detonation) sensor for engine management systems
• Walker Products engine sensor line backed by ISO 9001/IATF 16949 manufacturing standards
• OE-style application coverage for select Audi A4, A6, S4, Allroad Quattro, and Volkswagen Passat models
• Cross-references Beck/Arnley 158-0984 and Standard Ignition KS222 for the same application
• Part number 242-1139 for accurate catalog matching

Product Details

Walker Products has supplied fuel system and engine management components since 1946, with a focus on meeting or exceeding OEM standards and specifications. The 242-1139 knock sensor is part of that engine sensor lineup and is intended for vehicles that rely on precise knock detection to manage spark timing and reduce engine stress from detonation. This part number 242-1139 is listed for 1999-2005 Audi A4 and A4 Quattro, 2000-2001 Audi A6 and A6 Quattro, 2000-2002 Audi S4, 2001-2002 Audi Allroad Quattro, and 2000-2005 Volkswagen Passat.

Fits 1999 Audi A4, N/A; Fits 1999 Audi A4 Quattro, N/A; Fits 2000-2001 Audi A4, N/A; Fits 2000-2001 Audi A4 Quattro, N/A; Fits 2000-2001 Audi A6, N/A; Fits 2000-2001 Audi A6 Quattro, N/A; Fits 2000-2002 Audi S4, N/A; Fits 2001-2002 Audi Allroad Quattro, N/A; Fits 2000-2005 Volkswagen Passat, N/A.

Common Reasons to Replace

• Check engine light related to knock sensor circuit faults
• Engine pinging or spark knock under acceleration
• Reduced timing control from a failing detonation sensor
• Rough performance caused by inaccurate knock feedback
• Diagnostic trouble codes tied to knock sensor signal issues

Installation Notes and Tips

Verify the connector style, harness length, and application notes before installation. This listing includes fitment notes for certain Audi A4, A4 Quattro, A6, and A6 Quattro applications with a brown sensor body and 550 mm harness length, and a 1999 Audi A4/A4 Quattro chassis note of 8D-X-260 001. Confirm the vehicle’s engine and VIN details against the catalog before ordering.

Quality Assurance

Walker Products manufactures engine management components under ISO 9001/IATF 16949 certification and supports production with in-house engineering, product management, and technical documentation. The brand states its parts are produced to meet or exceed OEM standards and specifications.