The Honda fuel injector is how the gasoline is now supplied to the combustion chamber. No longer is the air and fuel mixed prior to entering the cylinder as it was in the past with carburetors and ported intake systems. There is a separate fuel injector for each cylinder on Honda vehicles being made today. Because of the small tubes and channels the fuel now has to move through before it is sprayed into the combustion chamber, the fuel itself has to be extremely clean. This is why the replacement of the fuel filter is more critical today than it has been in the past on older Honda models. The fuel injectors are controlled by the onboard computer which regulates the spraying of the fuel. This spray must be able to produce a fine mist so it can mix properly with the air inside of the combustion chamber. It can only be accomplished if the fuel injector is free of dirt and residue build up that can occur with contaminated fuel. The best path to preventing this build up is to add fuel injector cleaner to the gas tank on about every tenth fill up. It is possible to manually clean the outside of the Honda fuel injectors, but the inside of them can only be fully cleaned out with a cleaning additive being poured into the fuel tank. This is not an auto component that can be easily torn apart and cleaned. Because of this need to keep the internal parts of the injectors as clean as possible so they can function, the replacement of the Honda fuel filter on a regular basis is now more important than ever in accomplishing this goal. Otherwise, you'll be replacing your old injectors with new ones more regularly.