diablo question

when you get to the screen on the diablo where it says "reset parameters" does it set the car back to the custom tune minus the modifications done ( fuel, egr, trans settings, tire size, and such ) or to the stock tune?

My understanding is that while making changes to the tune, if you decide that you don't want to keep those changes, you press "reset parameters" to set the tune back to it's original (saved) settings. Nothing is actually changed to the tune that is installed in the vehicle until you tell the predator to install the tune. You can make changes to a tune and if you decide to not install the tune (for whatever reason), the changes you made to the tune will remain stored in the predator unless you choose "reset parameters".

so if i am understanding you correctly, resetting the parameters will put the car back to the tune written for the vehicle not the stock tune.

You're talking about when you load a custom tune how it'll ask that? It'll clear stuff like the tire size and any of the 'modified' parameters you set with the handheld that aren't written into the tune itself.

The Predator has tunes and a parameter change list. When you make changes to parameters it keeps a list of the changes. It does not modify the tune file on the Predator itself. It's when you write the tune to the car that it applies the change list to the copy being written to the car or PC. You can have a bunch of tunes on the Predator but there is only 1 parameter change list. That's why it asks you if you want to "reset parameters" when you select a different tune to work with.

Intresting