234-4407 Oxygen Sensor 1 and Sensor 2 Upstream & Downstream Fit 03 04 05 Chevrolet Tahoe GMC Yukon 4.8L 234-4407 Sensor 1 and sensor 2 Fit 03 04 05 Chevrolet Tahoe GMC Yukon 4.8L 2*Upstream & 2*Downstream Oxygen Sensor Direct Plug-In Replacement. Wires: 4. Warranty: One year unlimited miles. Kwiksen Oxygen Sensor is designed to detect the amount of oxygen in the exhaust stream. It is constructed from high quality stainless steel, porous polytetrafluoroethylene, fluorine rubber, aluminum oxide, high-grade platinum and ceramics. This Sensor features double protection layer, aluminum oxide trap layer, porous PTFE filter and stainless steel housing. It is manufactured with precision to meet OE standards. This oxygen sensor can be installed easily and ensures longevity.