A vehicle’s fuel delivery system has progressed quite a bit from the carburetor that used to sit on top of the engine. Today, modern vehicles feature precise fuel injection systems located on top of – or even inside – the combustion chamber. Restrictions in fuel flow, electrical problems with the injectors themselves or even dirty or contaminated fuel can all cause trouble. Fuel injectors will typically last between 50,000 and 100,000 miles. Much of this lifespan is determined by the type of fuel used and how often the vehicle’s fuel filters are changed. Some symptoms that your fuel injectors need replacing include an illuminated check engine light, a decrease in fuel efficiency, a smell of fuel (especially near the fuel injectors under the hood) and engine misfiring. Fuel injector replacement is a job best performed by an ASE-certified mechanic at a dealership service department or automotive service center.