The 4-wire narrow-band oxygen sensor is a replacement sensor for select 1998-2024 Audi, Porsche and Volkswagen applications. It signals whether the exhaust is running rich or lean so the engine computer can trim fuel delivery. A built-in heater brings the element to operating temperature quickly after a cold start.

Walker Products 350-34112 Oxygen Sensor Features:

• Fits 1998-2004 Audi A3; 2000-2001 Audi TT; 2001-2006 Audi TT Quattro; 2002-2004 Audi A6 Quattro, S3; 2002-2005 Audi Allroad Quattro; 2005 Audi A4
• Fits 2005-2006 Audi A4 Quattro; 2003-2006 Porsche Cayenne; 2000-2005 Volkswagen Passat; 2001 Volkswagen Beetle; 2003-2020 Volkswagen Polo; 2004-2006 Volkswagen Phaeton
• Also fits select Audi, Porsche and Volkswagen applications
• Sensor locations by application: B1S1, B1S2 (bank and sensor number)
• Used in both upstream and downstream positions, depending on application
• 4-wire narrow-band oxygen sensor
• Built-in heater for fast warm-up
• M18x1.5 threaded mounting with a 22 mm hex, 800 mm (31.5 in.) overall length
• Male/female oblong connector at the harness end with 4 spade terminals
• Platinum electrode layer with a protective coating against combustion residue