MIL?

Malfunction Indicator Light (MIL) eliminators prevent the check engine light from coming on. People rollin' with offroad X/H pipes will use them. Why u ask, so that they know if something else is setting off the CEL.
 
ebay has the MIL elim's for the 3.8 liter's. If her exhaust is tripping it you may want to consider having the emissions checked because then you either have a problem with emissions or they damaged her Oxygen sensors when installing it.