The 4-wire narrow-band oxygen sensor is a replacement sensor for 2003-2006 Ford Fiesta and 2003-2007 Ford Ikon with the 1.6L I4 engine in the upstream position. 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 350-34401 Oxygen Sensor Features:

• Fits 2003-2006 Ford Fiesta; 2003-2007 Ford Ikon with the 1.6L 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, 735 mm (28.9 in.) overall length
• Female square connector at the harness end with 4 bullet terminals
• Platinum electrode layer with a protective coating against combustion residue