hey im trading in my sonata but i have a problem
the dealer is 20mins away and my car now only goes 25mph. It can get up to 2nd gear but sticks at 25 still. The sensors had blown early a few months back but it still just shifted like a manual after that. Now it barely even moves-any idea what this could be?
The oil has been changed in a while but that doesnt seem like itd effect it that hard.

 

at 25 mph what rpm is the car at? with the car in park can you rev the engine to about 4k rpm? is the car misfiring?

 

as i mentioned,it blew a sensor(bs i believe,and/or input/output) so it shifts like a manual-i can get it up to 3x on the rpms,after that i need to take my foot off the gas to get it to shift up,even in park
no misfiring.
even with the sensor problem it could stil do upwards of 80-90mph,but over the last week or so it just gave out and wont do past 25

 

Mine had this problem and it was a faulty gas pedal. I have an '06 GLS so I don't know if it is any different but apparently they explained that my gas pedal was electronic and it malfunctioned. Warrenty luckily covered it

 

Well, not the gas pedal but possibly the throttle position sensor (TPS). The '01 Sonata does not have a throttle by wire, it's a cable.