Fuel injectors directly affect the air/fuel ratio for the engine and new fuel injectors do require a new or updated tune. We also suggest that you check the other component of the engine before installation. No special tools are required. It is easy to replace old fuel injectors. Each fuel injector has a protective cap that must be removed before use. Car Petrol Injection Nozzles 0280156086 For Blazer 2.4 Car Fuel Injector Nozzle Assy The injector's unique nozzle design reduces fuel injection noise and enhances cabin quietness. Its reinforced structure provides vibration , stable spray even on bumpy roads and adapting to various engine modifications. Fuel injectors effectively improve engine efficiency, delivering stronger power and lower fuel consumption, thereby enhancing overall vehicle efficiency and driving experience, providing a smoother ride. They save time and effort., Manufacturer: ZXCTQQS