4Pcs SG454 SG272 Upstream and Downstream Oxygen O2 Sensor Set Features: 1. Durable and easy installation. 2. Improve fuel economy and increase engine response. 3. High level of accuracy and sensitivity to protect safety of your car. 4. Designed to detect the amount of oxygen in the exhaust system. 5. Original standard, direct replacement for your old or broken one. 6. Pretested, precise and oxygen sensor. Lower emissions and eco-friendly. Specification: Item Type: Oxygen Sensor Material: Aluminum Color: As Pictures Show OE Number: SG454/234-4012 SG272/234-4018 Quantity: 2Pcs SG454, 2Pcs SG272 Package Weight: Approx. 495g Fitment: For V8 5.3L 2002 (excluding Canada Built Models) Downstream Upstream O2 Oxygen Sensor For V8 5.7L 1999-00 Downstream Upstream O2 Oxygen Sensor For Astro V6 4.3L 1996-97 Downstream Upstream O2 Oxygen Sensor For Avalanche 1500 V8 5.3L 2002 (excluding Canada Built Models) Downstream Upstream O2 Oxygen Sensor For C1500 Truck V8 5.0L 1996-99 with 4L60E 4 Speed Automatic Transmission Downstream Upstream O2 Oxygen Sensor For C1500 Truck V8 5.7L 1996-99 with 4L60E 4 Speed Automatic Transmission Downstream Upstream O2 Oxygen Sensor For C1500 Truck V6 4.3L 1996-98 Downstream Upstream O2 Oxygen Sensor For C2500 Truck V8 5.0L 1996-00 with 4L60E 4 Speed Automatic Transmission Downstream Upstream O2 Oxygen Sensor For C2500 Truck V8 5.7L 1996-00 with 4L60E 4 Speed Automatic Transmission Downstream Upstream O2 Oxygen Sensor For C2500 Truck V8 5.7L 1996-98 with 4L60E 4 Speed Automatic Transmission Downstream Upstream O2 Oxygen Sensor For Express 1500 Van V8 5.7L 1996-02 Under 8500LB GVW Downstream Upstream O2 Oxygen Sensor For Express 1500 Van V8 5.0L 1996-02 Downstream Upstream O2 Oxygen Sensor For Express 1500 Van V6 4.3L 1996-02 Downstream Upstream O2 Oxygen Sensor For Express 2500 Van V8 5.7L 1996-02 Under 8500LB GVW Downstream Upstream O2 Oxygen Sensor For Express 2500 Van V8 5.0L 1998-02 Downstream Upstream O2 Oxygen Sensor For Express 2500 Van V6 4.3L 1996-02 Under 8500LB GVW Downstream Upstream O2 Oxygen Sensor For K1500 Truck V6 4.3L 1996-98 Downstream Upstream O2 Oxygen Sensor For K1500 Truck V8 5.0L 1996-99 with 4L60E 4 Speed Automatic Transmission Downstream Upstream O2 Oxygen Sensor For K1500 Truck V8 5.7L 1996-99 with 4L60E 4 Speed Automatic Transmission Downstream Upstream O2 Oxygen Sensor For K2500 Truck V8 5.7L 1996-98 with 4L60E 4 Speed Automatic Transmission Downstream Upstream O2 Oxygen Sensor For K2500 Truck V8 5.0L 1997-98 with 4L60E 4 Speed Automatic Transmission Downstream Upstream O2 Oxygen Sensor For Silverado 1500 V8 4.8L 2000-02 (US Built Models) Downstream Upstream O2 Oxygen Sensor For Silverado 1500 V8 5.3L 2000-02 (excluding Canada Built Models) Downstream Upstream O2 Oxygen Sensor For Silverado 1500 V8 5.3L 1999 Downstream Upstream O2 Oxygen Sensor For Silverado 1500 V8 4.8L 1999 Downstream Upstream O2 Oxygen Sensor For Silverado 1500 V6 4.3L 1999-01 Downstream Upstream O2 Oxygen Sensor For Silverado 1500 V6 4.3L 2002 (8th Vin Digit X) Downstream Upstream O2 Oxygen Sensor For Silverado 1500 HD V8 6.0L 2001 Downstream Upstream O2 Oxygen Sensor Passenger Side For Silverado 2500 V8 5.3L 2000 (excluding Canada Built Models) Downstream Upstream O2 Oxygen Sensor For Silverado 2500 V8 5.3L 1999 Downstream Upstream O2 Oxygen Sensor For 1500 V8 5.3L 2000-02 (excluding Flex Fuel) (US Built Models) Downstream Upstream O2 Oxygen Sensor For C1500 V8 5.7L 1996-99 with 4L60E 4 Speed Automatic Transmission Downstream Upstream O2 Oxygen Sensor For C2500 V8 5.7L 1996-99 with 4L60E 4 Speed Automatic Transmission Downstream Upstream O2 Oxygen Sensor For K1500 V8 5.7L 1996-99 Downstream Upstream O2 Oxygen Sensor For K2500 V8 5.7L 1996 Downstream Upstream O2 Oxygen Sensor For Tahoe V8 5.3L 2000-02 (8th Vin Digit Z) (US Built Models) Downstream Upstream O2 Oxygen Sensor For Tahoe V8 4.8L 2000-02 (US Built Models) Downstream Upstream O2 Oxygen Sensor For Tahoe V8 5.7L 1996-99 with 4L60E 4 Speed Automatic Transmission Downstream Upstream O2 Oxygen Sensor For C1500 Truck V8 5.7L 1996-99 with 4L60E 4 Speed Automatic Transmission Downstream Upstream O2 Oxygen Sensor For C1500 Truck V8 5.0L 1996-99 with 4L60E 4 Speed Automatic Transmission Downstream Upstream O2 Oxygen Sensor For C1500 Truck V6 4.3L 1996-98 Downstream Upstream O2 Oxygen Sensor For C2500 Truck V8 5.7L 1996-99 Downstream Upstream O2 Oxygen Sensor For C2500 Truck V8 5.0L 1996-98 Downstream Upstream O2 Oxygen Sensor For K1500 Truck V6 4.3L 1996-98 Downstream Upstream O2 Oxygen Sensor For K1500 Truck V8 5.0L 1996-99 Downstream Upstream O2 Oxygen Sensor For K1500 Truck V8 5.7L 1996-99 Downstream Upstream O2 Oxygen Sensor For K2500 Truck V8 5.7L 1996-99 Downstream Upstream O2 Oxygen Sensor For K2500 Truck V8 5.0L 1998 Downstream Upstream O2 Oxygen Sensor For Safari V6 4.3L 1996-97 Downstream Upstream O2 Oxygen Sensor For 1500 Van V8 5.0L 1996-02 Downstream Upstream O2 Oxygen Sensor For 1500 Van V6 4.3L 1996-02 1996-02 Downstream Upstr