Here we go again; Sometimes when I modify the tune, I adjust the trans. shift firmness. On occasion, the predator comes back as failed to adjust, so I try again, then it says adjusted. That day I modified the tune, I test drove and at 1/3 throttle I had a good 1-2 shift. I rolled on at a stop sign, went 3/4 throttle, goes good, then slows for shift, then acceleration comes in again, feels like throttle is disabled for a second, or ignition turned off. It is not a flare up as in trans slippage, it seems to be a safeguard from Daimler-Benz, I predict. I hope this thread sounds familiar to you lxers! Any ideas? Mag05