The 4-wire narrow-band oxygen sensor is a replacement sensor for 1996-1998 Mercury Villager and 1996-1997 Nissan Quest with the 3.0L V6 engine in the downstream 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 350-34378 Oxygen Sensor Features:

• Fits 1996-1998 Mercury Villager; 1996-1997 Nissan Quest with the 3.0L V6 engine
• 4-wire narrow-band oxygen sensor
• Built-in heater for fast warm-up
• M18x1.5 threaded mounting with a 22 mm hex, 1290 mm (50.8 in.) overall length
• Female square connector at the harness end
• Platinum electrode layer with a protective coating against combustion residue