A malfunctioning EGR valve can cause your SN-95 Mustang to buck on acceleration, run rough, and decrease your gas mileage. Pick up one today for your 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, and 2004 Mustangs with 4.6L and 5.0L motors.