The 5-wire wide-band oxygen sensor is a replacement sensor for 2015-2018 BMW M3, 2015-2020 BMW M4 and 2019-2021 BMW M2 with the 3.0L I6 engine in the upstream position. It measures the exhaust air-fuel ratio across a broad range so the engine computer can meter fuel precisely. A built-in heater brings the element to operating temperature quickly after a cold start.

Walker Products 250-25123 Oxygen Sensor Features:

• Fits 2015-2018 BMW M3; 2015-2020 BMW M4; 2019-2021 BMW M2 with the 3.0L I6 engine
• Sensor location by application: B1S1 (bank and sensor number)
• 5-wire wide-band oxygen sensor
• Built-in heater for fast warm-up
• M18x1.5 threaded mounting with a 22 mm hex, 850 mm (33.5 in.) overall length
• Male/female rectangle connector at the harness end with 5 blade terminals
• Platinum electrode layer with a protective coating against combustion residue