99-04 Mustang Fuel Filter Replacement - Did It Myself My used 99 Mustang GT was having some trouble with warm starts. One possible candidate is the fuel filter. Fortunately 99-04 Mustang fuel filter replacement is pretty easy. Since it’s an old car, even if the fuel filter wasn’t the problem, it’s good preventative maintenance. I went ahead and did the work. 1999-2004 Mustang Air, Oil & Fuel Filters | AmericanMuscle Shop our selection of 1999-2004 Mustang Air, Oil and Fuel Filters. Get the look and utility you need with new Air, Oil and Fuel Filters at americanmuscle.com.