what is a burp? falling on it's nose or what? Sounds like throttle lag.... try the throttle reset and see if it improves. Remember, the car has a memory, so if you drive it slow it will react to slow. throttle reset, and drive the hell out of it. See if you see any improvement. I use to think it was bullshit, but, I learned it wasn't. They will become doggy not driven. If that doesn't do it, you may have a CPS starting to fail as well. And there is always the controversial sprint booster that can be had...no throttle lag with it....