NGK 21555 NTK Oxygen Sensor 4-Wire Heated 18mm Thread O2 Sensor

The NGK 21555 NTK oxygen sensor (also called an O2 sensor or air/fuel ratio sensor) is an OE-identical, direct-fit replacement. It monitors the oxygen content of the exhaust and sends voltage signals to the engine management system. The system uses those signals to regulate the air-fuel ratio for efficiency and lower emissions.

Key Features:

• Sensor type: Narrow band, heated, with 4 wires
• Thread: 18 mm (M18-1.5), non-flanged, with a 7/8 in. wrench size
• Wire length: 550 mm (21.75 in.)
• Connector: OE-specified, water-resistant, trapezoid-shaped female connector with 4 blade terminals, so you can plug it in directly with no cutting or splicing
• Fast light-off: The integrated heater and ceramic sensing element reach operating temperature quickly. This allows earlier closed-loop activation and lower cold-start emissions.
• Durable element: A dual-coated platinum interface and a contaminant-resistant overcoat help protect the element against poisoning
• Protective housing: The corrosion-resistant housing has a porous PTFE filter. It lets atmospheric oxygen in but keeps water and engine contaminants out.

NGK/NTK is a leading OEM oxygen sensor supplier, and each sensor is tested for quality and durability. Replacing a worn sensor can help restore fuel economy, drivability and smog-test compliance.