This 4-wire narrow-band oxygen sensor fits 1989-1991 Peugeot 405 with the 1.9L I4 engine 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 350-34420 Oxygen Sensor Features:

• Fits 1989-1991 Peugeot 405 with the 1.9L I4 engine
• Sensor location by application: B1S1 (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, 1225 mm (48.2 in.) overall length
• Male rectangle connector at the harness end
• Platinum electrode layer with a protective coating against combustion residue