My es300 1998 runs jerky at 5to10 mph just paid 800 dollars to fix and they cannot find the problem what could it be?

I just experience a similar problem with a 2003 Outback to the point where one would expect a hydraulic clutch was failing. One dealer and one transmission shop both thought that it was a mechanical problem while another dealer rewrote the PCM for latest updates and totally eliminated the problem for about $60. A friend advised me that they had the same type of problem on a new model Sebring that was also solved by programming a computer You need to find a dealer who can diagnose the electrical as well as the mechanical It does not cost 800 to diagnose a transmission problem.