Rear o2 cheater
 

I know people in the past have bought o2 simulators but those are no longer availiable so found this write up for a cheater for the handy enthusiast who has eliminated there cat or put on a high flow

Http://www.paladinmicro.com/MustangMILEliminator.htm

I believe o2 cheaters do NOT work on a 2005 because they read more variables.

Great information though :)