Fuel filters must be changed regularly, and injection systems must be kept clean. Fuel injection and system cleaning ensures that your engine operates efficiently. Gasoline leaves varnish deposits throughout the fuel system. They build up as gas flows through the system, and they form a restriction within the injector nozzles. This restriction causes the injector to dribble (rather than spray) fuel into the combustion chamber, decreasing gas mileage as well as performance. In addition, it becomes harder to start the vehicle when it’s cold.
Finally, when gas is not burned completely within the combustion chamber, the unburned gas forms a solid, hard carbon residue that soaks up fuel from the air-fuel mixture as it enters the combustion chamber, thus causing a lean burn condition. The O2 sensor sends a “lean fuel” message to the computer; the computer responds by dumping more fuel into the engine, the carbon residue soaks up more fuel, and a vicious cycle is established. Next, the O2 sensor gets “coked up” from carbon contamination; the catalytic converter gets overloaded with gas because it can’t process the gas fast enough, so a rock of carbon forms in the converter. This carbon buildup restricts exhaust flow and dramatically reduces power. The dominos fall on and on until the car fails to start because you did not maintain the fuel system according to factory standards. This should illustrate clearly why maintenance is so important to the life of your vehicle.