This 4-wire narrow-band oxygen sensor fits 1988-1993 BMW 535i, 1988 BMW 535is, 1988-1989 BMW 635CSi, 1988-1992 BMW 735i, 735iL and 1991-1993 BMW M5 in the upstream position 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 350-34062 Oxygen Sensor Features:

• Fits 1988-1993 BMW 535i; 1988 BMW 535is; 1988-1989 BMW 635CSi; 1988-1992 BMW 735i, 735iL; 1991-1993 BMW M5
• Engine coverage includes 3.5L I6, 3.6L I6 applications
• 4-wire narrow-band oxygen sensor
• Built-in heater for fast warm-up
• M18x1.5 threaded mounting with a 22 mm hex, 1495 mm (58.9 in.) overall length
• Female circle connector at the harness end
• Platinum electrode layer with a protective coating against combustion residue