Kwiksen Oxygen O2 Sensor 234-4112 Downstream For 2002 2003 Chevrolet Trailblazer EXT GMC Envoy XL 4.2L Direct Plug-In Replacement Cross Reference Part Number: 234-4112 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.