If you've modified your engine beyond the basics, such as installing a turbo or nitrous kit, it's likely time to upgrade your Audi S4 fuel injectors. Getting the proper amount of fuel to your engine is critical in regards to performance and extending your engine's life, and installing high-performance Audi S4 fuel injectors is one very vital step in the process.

One of the best things to ever happen to Audi S4 engines is fuel injection, but even fuel injectors can stop functioning properly over time. Even worse, they might still be operating correctly, but simply aren't providing enough fuel to your modified engine, resulting in a lean condition and hindered performance. A good set of aftermarket Audi S4 fuel injectors, paired with an upgraded fuel system and engine management, will help you attain your performance goals and keep your engine in optimal shape.

Q: What are fuel injectors? Why buy fuel injectors?
A: Fuel injectors are the primary means of getting gasoline into the motor in non-carburated vehicles. The injectors are mounted in the intake manifold so that they spray fuel directly at the intake valves. A fuel rail supplies pressurized fuel to all of the injectors. Sometimes largers injectors are needed if you are customizing your performance set-up. For example, when running nitrous oxide, more boost, or a high revving naturally aspirated motor, larger fuel injectors are needed. Larger injectors are needed so that they can supply the engine with more fuel in order for it not to lean out.

Q: Do fuel injectors come in sets of 4?
A: Fuel injectors are sold individually, so you have to buy the number of injectors necessary for your car. Four-cylinder cars would use four injectors, and six-cylinders would use six fuel injectors, and so on.

Q: How do you install fuel injectors?
A: Fuel injectors are installed by unplugging the harness from the fuel rail and popping out the factory injectors. New o-ring seals should be installed at this time to prevent leaking with the new injectors.