This 4-wire narrow-band oxygen sensor fits 2016-2018 Mazda CX-3, MX-5, MX-5 Miata, 2016 Scion iA, 2015-2019 Toyota Yaris and 2017-2018 Toyota Yaris iA in the downstream 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 350-34987 Oxygen Sensor Features:

• Fits 2016-2018 Mazda CX-3, MX-5, MX-5 Miata; 2016 Scion iA; 2015-2019 Toyota Yaris; 2017-2018 Toyota Yaris iA
• Engine coverage includes 1.5L I4, 2.0L I4 applications
• Sensor location by application: B1S2 (bank and sensor number)
• 4-wire narrow-band oxygen sensor
• Built-in heater for fast warm-up
• M18x1.5 threaded mounting with a 22 mm hex, 400 mm (15.7 in.) overall length
• Female square connector at the harness end with 4 spade terminals
• Platinum electrode layer with a protective coating against combustion residue