The replacement knock sensor is made for select 2004-2015 Audi applications in the rear left position. It detects the vibration frequencies of engine detonation so the engine computer can retard ignition timing.

Walker Products 242-1156 Knock Sensor Features:

• Fits 2004-2005 Audi Allroad Quattro; 2004-2009 Audi S4; 2005-2006 Audi A6 Quattro; 2007-2011 Audi S6; 2007-2009 Audi S8; 2013-2015 Audi RS5
• Engine coverage includes 4.2L V8, 5.2L V10 applications
• Female oblong electrical connector with 3 blade terminals
• 406 mm (16 in.) overall length
• 301.498 mm (11.9 in.) wiring harness
• Includes wiring harness
• Mounting hardware not included