[Gmecm] New ROM-code in a 1227747?

[Per Lonnborg]

Hi, 

is it common/possible out there to insert altered ROM-code in a "new" ROM to get new funtionality in my TBI?

My plan is to use the 
EGR(A4) and/or the EAC(C2) outputs to regulate my electric radiator fan instead. ( Since the 747 is put in a ?75 Monza, i dont need these 
emission components by swedish law).

For what I have seen, the code for EGR activation is starting at EB59 which would be ROM-code.

/Per