I read as much as I could find, didn't see the answer;

if you install the ls4 throttle body on your current tune, will the car fire up and run, or do you have to change the scaler before attempting to fire up?

 

Yes u can. The scaler does just what it sounds like. It rescales the size the the ecm expects the air to go through making the throttle input smoother. I just started mine up, revved the car, changed scaler, and repeated until I was happy. Just start at the recommended scaller setting to make it easier/faster.

 

He's correct ^^

You'll be fine if you just start the car. May run just a tad lean.. & pretty difficult to drive.. But it's not like your car won't be driveable