Can i swap the ECM from a 97 to a 96 grand Cherokee 4.0 both federal emissions and both with security and if so will it work without reprogramming

 

You should be able to do so, but you'll need to have the ECM programmed to your Jeep's VIN (you SHOULD be able to use ANY '96-'98 ECU, as long as it comes from a Grand Cherokee ZJ with the 4.0). They started the programming in '96. The '93-'95 models WON'T work because they DON'T have to be programmed, and are far less advanced than the ECU's in the '96-98 models.

-Vince