On my 2000 SVT as soon as the fuel level goes under half a tank, my car will "Buck and bog" in 1st, 2nd, and sometimes 3rd, under hard acceleration. I just did a full tune up w/autolite plat. plugs, stock wires new fuel filter, etc. Im still having the same problem. Autozone said there are no codes showing when they read the codes. This is really starting to piss me off!!! I need help!!!!!!