Originally Posted by GaryTucker
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.
Good point. I think this is only viable when you have a mildly modded car. I.E. long tubes, CAI, full exhaust. The car will run fine without a tune but will have a check engine light or will not have all the performance it could get from the mods.
In addition it would not be very useful for the reasons you stated if you have a major engine failure. Were it could be useful would be for a broken CV joint or a failed output shaft on a trans. Things that GM should not take a tune into consideration for warranty but they are...