The fuel injector is a nozzle-and-valve system injects the correct amount of fuel into the engine. There is an electronic sensing device on vehicles equipped with fuel injection systems that determines how much fuel the injector should inject into the combustion chamber of the engine. Most modern vehicles have on fuel injector per cylinder.
The most common problem with the fuel injector is that is becomes clogged with dirt and debris. The fuel filter should be replaced periodically to prevent clogging of the fuel injector and there are also fuel injector cleaners available that can be poured into the gas tank, run through the fuel system, and clean the injectors.
Most manufacturer factory warranties will cover the fuel injector under their bumper-to-bumper warranty. For extended coverage, an extended auto warranty is an option. The fuel injector is covered under the more comprehensive plans.