Keep your SN95 engine properly cooled with replacement 1994-2004 Mustang cooling system sensors. Coolant temperature sensors are a very important part of your cooling system. These sensors relay temperatures back to the computer to determine timing, EGR flow, and air/fuel ratio. Neglecting a faulty sensor can cause major problems to your engine. Temperature sending units relay information to your gauges to let you know how hot/cold your motor is. Not knowing if your engine is overheating can lead to serious damage. These sensors fit 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, and 2004 Mustangs.