I've read many times that with the predator or any handheld tuner that even if you put the stock tune back in some of the other tune remains and the only way to go back to stock 100% is a dealer reflash. Is this true?

 

You read that many times? I've never heard of it.

 

I've heard that before, particularly concerning Predator tuners. But I don't know how true it is. You may get better responses on James' website. http://www.diablosporttuning.com/forums/

Nick

 

to my understanding Predator has 2 data banks to read from... one saves data from your car about a current tune and the other holds a performance tune that is either uploaded by Diablosport directly from purchase, or later on down the road if you decide to get custom tunes from them.

So here's what happens... when you first hook up the Predator you have to save your vehicle data right??? It takes and stores your stock tune in the "current bank" and marries your VIN. So let's say you put the base performance tune into your PCM, that would mean you have the Base diablo tune in the performance bank and your stock tune in the saved data bank. Now further down the road you start modding (headers, intake, MAFs, cams, etc) these will not be optimized with the base predator tune.

When you do a custom tune, you save the vehicle's current tune (whatever condition it may be in, rich or lean, etc) which I believe overwrites the previous data in the "Saved data bank" (ie. your stock tune). you send that to diablo, and then they send you back a modifies performance tune which overwrites the exisiting base diablo tune in the performance data bank. So now you have 2 totally different tunes in your memory banks

This was discovered when I dynoed and my "stock tune" yielded that same exact results with my performance tune. Same AFR, same power and torque curve (an I mean identical!) I put in my custom tune from diablo and right afterwards saved current vehicle data so i could send back to diablo if my dyno came out wierd. my first run was with the perf tune, second run I wanted to see how much over stock my perf tune helped out. so I followed to instructions to "put back" the stock tune and it was nowhere to be found... and yes the performance tune did do something so it's not one of those "I've been on the stock tune the whole time" things

So after this little experiement, if you want a true stock tune... GM reflash