I took my car to the dealer this morning. They callled and said that they need to replace the throttle position censor and its going to cost $350. Is this something only the dealer can replace?
Absolutely not. Most TPSs could be replaced by someone of average mechanical ability and a few simple hand tools. I don’t know the exact set-up on the Sorento and some are a bit more complicated than others - but you can go to any independent mechanic.
In fact, you might ask them to double check the diagnosis. What is the car doing and what is the basis for them pointing to the TPS?
It was making a load noise when turning sharply, like a thud, thud, thud. Pretty scary actually. I was first told at another auto shop that it was likely the CV Joint, they then called later and said it was popping in and out of 4WD. That is what lead me to take it to the dealer. The check engine light is on and that is the code they are getting for the throttle position censor. He said this should hopefully take care of the problems its having. I am crossing my fingers. 
I can’t wait to see how this one turns out. A TPS sensor is being blamed for causing a thud sound when turning? 
NikkiSix (aren’t you missing an X?) - I have no idea why the popping out of 4WD would have you at the dealer - unless this is all under a 10yr/100K mile warranty - ?
In any case, ok4450 is right. Within the space of about a week you’ll most likely still have a thudding noise and a check engine light. There isn’t a code that can tell you that a TPS is bad. It might refer to the TPS signal or circuit - but the computer has no idea exactly where the issue is. Ask them what the actual code is - they look like “P1234”
A new TPS won’t do a thing for the thud. Ask them to explain - in exact and precise detail - how a bad TPS leads to a thudding noise when you turn. Unless you need warranty work I’d just get it out of there.
Is This A 3.5L Engine ?
That’s a lot of money for a TPS. On the 3.5L 2003 - 2006 Kia Sorentos, Kia had to relaease a “revised” TPS because some original sensors were experiencing excessive wear of the inner elements.
Turn off engine and take off engine cover and disconnect TPS connector.
Remove 2 screws and remove TPS from the throttle body.
Reverse the procedure to install new TPS.
Hook up scan tool and rubber cap on idle screw and adjust according to instructions.
CSA