OK.I have U7194 v9r03 . I tried again, Predator tune & 87 Octane tune. I get the "Engine Power is Decreased" message and my truck won't start. I disconnected the negative battery post and waited 10 minutes, hooked it back up and still no start. Reinstall factory tune and it starts and runs normal ...

I think it is 8r09, I'm @ work now and can't check it. I tried it without removing the fuses, same result. Tried the 87 octane tune, same again.
Monte, are you saying install the tune and then disconnect/reconnect the battery and I'll have the tune? Is this something I'll have to do everytime I ...

I just purchased a U7194 for my 2007 Silverado NBS 4.8. I entered the "Diablo Tune" and I get a "Engine Power Decreased" message on my dash and my truck won't start. I removed the Onstar, stereo and amp fuses. I am able to restore foctory tune and it will start. Any Ideas...?