About Compatibility: 2004 for Buick for Rainier 4.2L,2002-2004 for Chevrolet for Trailblazer 4.2L,2002-2004 for Chevrolet for Trailblazer EXT 4.2L,2002-2004 for GMC for Envoy 4.2L,2002-2004 for GMC for Envoy XL 4.2L,2004 for GMC for Envoy XUV 4.2L,2002-2004 for Oldsmobile for Bravada 4.2L. About Fuel Injector: Using high-performance raw materials, the porous injector can achieve precise injection to save fuel to extent.. About Installation:Fits and works better like original OE parts, achieving perfect replacement, simple installation not only saves time but also brings better driving experience.. About Working principle: The fuel injector transports petrol from the fuel tank to the engine cylinder to provide power for the vehicle. After atomizing the fuel, it ensures that the fuel is evenly distributed in the combustion chamber, improves fuel economy..
