2002 prius loses power, after 4 tries check engine clears

check engine light turns on, car slows down , eventually stops. After i turn engine off and start it again
check engine clears ok, but only after the 4th try or so. this happens more often from spring to fall, about 5-7 times per trip. during winter time it happens about 2-3 times a week. also if i drive fast, for example on the freeway this NEVER happens. took it to 3 different dealers here in Romania, they cannot figure it out. the only thing they read in the history of the car it shows problems with acceleration pedal.
please help ! other than that car runs very nice, it is a 2002 prius, sedan.

 

thank you for your answer. i read up on the Big Hand syndrome, it looks like this is the problem i have.
however here in Romania nobody wants to work on Hybrid
so i bought the part but am not sure this is what i need:

'01-03 Toyota Prius G1 Gas Accelerator Pedal Assembly 78010-47090 A36 OEM'

I am new on prius chat, sorry for the late answer, thank you again