Originally Posted by BlackinBlack
If that was the case... then keep the factory ECM stock and Mod the spare one. Not Rocket science.
What everyone fails to think about is what happens with a catastrophic failure? Sure you can slap that old ECM in...but if it isn't reading anything near what could have caused your major failure...then do you think the dealer will buy it? Some items have to have a run cycle to reset...so that ECM that's been on the shelf for 6 months still shows something out of kilter for the situation your car is in.
Even the "swap the ECM" trick isn't 100% foolproof and only seems logical if you are only running a CAI, Catback, and Tune. Anything more and your car is going to run like crap when you "untune it" to take to the dealer.