The 4-wire narrow-band oxygen sensor is a replacement sensor for 1992-1995 BMW 325i, 325is, 1993-1994 BMW 740i, 740iL, 1994 BMW 530i, 540i and 1995 BMW M3 in the upstream position. 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 350-34025 Oxygen Sensor Features:

• Fits 1992-1995 BMW 325i, 325is; 1993-1994 BMW 740i, 740iL; 1994 BMW 530i, 540i; 1995 BMW M3
• Engine coverage includes 2.5L I6, 3.0L V8, 3.0L I6, 4.0L V8 applications
• 4-wire narrow-band oxygen sensor
• Built-in heater for fast warm-up
• M18x1.5 threaded mounting with a 22 mm hex, 330 mm (13 in.) overall length
• Female circle connector at the harness end
• Platinum electrode layer with a protective coating against combustion residue