PartsSquare 4pcs Oxygen O2 Sensor 234-4336 234-4337 Upstream&Downstream For 2006 2007 Chevrolet Silverado 1500 5.3L Direct Plug-In Replacement Cross Reference Part Number: 234-4336, 234-4337 Position: Please check compatibility in Description Warranty: One Year Unlimited Miles This is Brand New High Quality Aftermarket Product. Meet the professional specification as OEM parts, for stable performance durable service.