You can swap computers(non-egr computer) or swap intake and exhaust manifold to put EGR back on

The 2002 computer will have a more aggressive spark setting since it has EGR system to cool cylinders and avoid pinging/knocking

The 2003 computer will have a different method to avoid that, with no EGR

DPFE sensor is connected to the exhaust tube to EGR valve, as computer opens EGR valve there is a pressure drop in the tube, DPFE reads that pressure change, so computer "knows" how far open EGR valve is, that allows computer to "know" how much exhaust is being added to intake to cool the cylinders.
There is no good way to "fake" this because its too closely monitored, i.e. small changes will set codes

 

 

Because you have PATS (Securilock) which is an anti-theft system. This system has three parts for 2002 and 2003, the key, the transceiver, and the vehicle's computer. All three are programmed together. If any of these pieces are swapped out, they will no longer match and the truck will not start. When swapping computers, you need all three of these components from the donor vehicle, or you need to have the computer reprogrammed to recognize the new key and/or transceiver.

 

 

Usually Ford, but you'll have to call and make sure they still have the ability to flash something this old. Keep in mind the fees you will encounter since it is a technical service. Otherwise, you might have to find an external source that has the equipment to do so.