The 4-wire narrow-band oxygen sensor is a replacement sensor for 2004-2008 Chevy Astra and 2006-2008 Chevy Vectra 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 350-34264 Oxygen Sensor Features:

• Fits 2004-2008 Chevy Astra; 2006-2008 Chevy Vectra
• Engine coverage includes 2.0L I4, 2.4L I4, 2.8L V6 applications
• 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, 350 mm (13.8 in.) overall length
• Female oblong connector at the harness end with 4 spade terminals
• Platinum electrode layer with a protective coating against combustion residue