This 4-wire narrow-band oxygen sensor fits 1996-1999 BMW 328i, 328is, M3, 1996-1998 BMW 528i, 1997-2000 BMW Z3, 1998-1999 BMW 323i, 323is and 1999-2000 BMW 323ti and 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 350-34095 Oxygen Sensor Features:

• Fits 1996-1999 BMW 328i, 328is, M3; 1996-1998 BMW 528i; 1997-2000 BMW Z3; 1998-1999 BMW 323i, 323is; 1999-2000 BMW 323ti
• Engine coverage includes 2.5L I6, 2.8L I6, 3.2L I6 applications
• Used in both upstream and downstream positions, depending on application
• 4-wire narrow-band oxygen sensor
• Titania sensing element
• Built-in heater for fast warm-up
• M18x1.5 threaded mounting with a 22 mm hex, 990 mm (39 in.) overall length
• Male circle connector at the harness end
• Platinum electrode layer with a protective coating against combustion residue