
Originally Posted by
blindsquirrel
There could be conflicts with, literally (using 'literally' in the literally correct way here), every other module in the car. If there are conflicts and the modules are the same service number as the '09-up then they can be reprogrammed, if they are different they'll need to be replaced, if that's possible (physical fitment is usually the same year-to-year but not always). If this is in the vehicle GM put together, that is. If it's a swap and ECM is standalone it doesn't matter because there's no other modules except the TCM if there is one (early ECM/OS only works with early TCM/OS, and late with late, and it's not unusual for a T43 to be a different service number on either side of the early/late breakpoint).
TCM if it has one, cluster, airbags, BCM, ABS, FPCM if it has one, etc. If the ECM shares the network with it it could refuse to play nice, and unless you can find the exact individual who has done the same swap on the same vehicle, you won't know if it can be made to work until after you swap it and exhaust all the potential fixes.
shorter version: I do not think this is a wise solution to a seemingly minor annoyance like whatever with the O2 offsets.