The oxygen sensor installs in the upstream position on 1986-1987 BMW 325, 1987-1988 BMW 325is, 1988 BMW 325i, 325iX and 528e. 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 350-34030 Oxygen Sensor Features:

• Fits 1986-1987 BMW 325; 1987-1988 BMW 325is; 1988 BMW 325i, 325iX, 528e
• Engine coverage includes 2.5L I6, 2.7L I6 applications
• 4-wire narrow-band oxygen sensor
• Built-in heater for fast warm-up
• M18x1.5 threaded mounting with a 22 mm hex, 615 mm (24.2 in.) overall length
• Male circle connector at the harness end
• Platinum electrode layer with a protective coating against combustion residue