Walker Products Engine Management and Oxygen/Air-Fuel sensors have been engineered and developed to be an Original Equipment Manufacturers replacement for many vehicles worldwide. Every part number is manufactured for the specific application, fitment position on the vehicle, and will provide the relevant diagnostic system feedback as required by the ECU. Newer vehicles will store fault codes in the ECU, some will relate to the affected sensor and its associated systems. A failed sensor might make itself known by causing the engine to run poorly, increase fuel consumption, exhaust emissions, or illuminating a (MIL) malfunction indicator light. The sensor, wiring harness, and connector should also be checked for physical damage. This will most likely also cause their operational life to be shortened. We are an Automotive ISO9001/TS 16949 certified company, with un-paralleled customer service, marketing, and shipping. Our electronic and paper catalogs are designed for today's fast paced marketplace, along with our eye catching packaging. Since 1946, Walker Products has been the number one choice for the engine management sensors and fuel system components needed for your vehicle. Vehicle Fitment: 2000-2009 Buick Allure 3.8L Chevrolet K2500 7.4L Chevrolet K3500 7.4L Buick LaCrosse 3.8L GMC Savana 3500 8.1L GMC Sierra 1500 HD 6.0L GMC Sierra 1500 6.0L GMC Sierra 2500 HD 6.0L8.1L GMC Sierra 2500 6.0L GMC Sierra 3500 6.0L8.1L Chevrolet Silverado 1500 HD 6.0L Chevrolet Avalanche 2500 8.1L Chevrolet Silverado 2500 HD 6.0L8.1L Chevrolet Silverado 2500 6.0L Chevrolet Silverado 3500 6.0L8.1L Chevrolet Suburban 2500 6.0L8.1L GMC Yukon XL 1500 6.0L GMC Yukon XL 2500 6.0L8.1L GMC Yukon 6.0L Chevrolet C2500 7.4L Chevrolet C3500 7.4L Chevrolet C3500HD 8.1L Cadillac Escalade EXT 6.0L Cadillac Escalade 6.0L Chevrolet Express 3500 8.1L Pontiac Grand Prix 3.8L