bugnout wrote:
If you have 2 ECU's seems like the perfect answer, Switching back and forth is not big deal, but doesn't the ECU contain data on the last X cycles?
So switching back to a stock ECU before taking to the dealer might be as big a tip off as leaving a tuner box installed. If there is date info or time since last cycle info. I'm concerned that bringing in my KJ to the dealer because it threw a code, and then have them notice that the KJ's ECU says that it has been sitting on blocks for the last 6 months?
But... If the tuning is undetectable, no reason to have a second ECU except to have a spare one when I send mine in for a new tweak to the programming.
Thoughts?
"then have them notice that the KJ's ECU says that it has been sitting on blocks for the last 6 months?"
I'd like to see that P code

Wouldn't mind it just to see the tech's reaction. But you raise an interesting question. Does the odometer reading stay in the ECU or elsewhere? Might be a bit of a problem if you come in with 20K fewer miles than the last visit, on the same VIN...
As for messing with the dealer - one could fabricate a bracket for the 2nd ECU, and put both ECU's in next to each other - but the 2nd one would only have a dummy connector on it. Install a big red handled copper A-B thow switch and label the ECU's "Primary and Backup".
If only one could videotape this setup at the dealership when getting the TSB de jour. You could always tell them you throw the ECU switch to Backup when the jumping/bucking/shuddering starts and that stops it. Then tell them an out of town dealer installed the 2nd ECU as part of the latest TSB flash update
