another?throttle position senser were??

trying to replace so many parts for a 2000 accent.im getting like 4
parts.need help on how to replace a throttle position sensor.were is this
part in the engine?and and also replaceing a fuel filter. that i can do! i
post a question about my accent not getting reverse.it still doesnt work
well.i did ever thing fluid checked good.theres no funny sound on
trans.checked the fluid color pink.no small metal parts in the fluid.fluid
smell no brunt.all gears shift fine.except 3rd gear every time it hits 3rd
gear pass at 3000rpms.the gears shifts hard like it jerks.i dont hear the
gears make a clunk sound on 3rd?this after noon sitting for 7 hours my
girlfriend told me she put it in reverse and shift and the car start to
back up to fast then normal speed she was not pressing on the gas pedal
when going in reverse.then last week on the freeway straight going about
70 mph when try to speed up pressing the gas pedal to the floor to pass a
car.the rpm drop to 2000rpm lost speed i felt it shift gears like it went
to 3rd while pressing the gas pedal.when i relaese the gas pedal then i
pushed the gas pedal half way it went back to 4rd gear.normal speed.could
this be a senor?or transmission problem? thanks

 

It's very doubtful that a throttle position sensor would cause a
transmission condition similar to slippage. I don't feel good about
knowing the real specifics of your condition, but it sure sounds like the
transmission is slipping.