Started a new thread that answers the question rather than having to read through a bunch of people saying "Do a search, its been answered before"
So I had the typical crap happen with my 99 GS300 going into limp mode and only driving it around at 10% throttle like apparently a lot of these cars have an issue with.
I FIXED IT.
Did the typical stuff to research what it was, got the part numbers, used an ohm meter to make sure what it was, THEN called the dealership.
Here is something interesting that I found out, if you go through Lexus to get these parts, you will spend 5-15% more than if you do your research and head to a Toyota dealership with the part numbers. These sensors are the same on three or four different cars, BUT year does matter so do your research.
After I fixed everything, I took the throttle body off and cleaned the hell out of it (if you have this issue, you probably have a lot of carbon in yours as well so clean it)
Its important to make sure battery terminals are unhooked before you mess with it, disconnect the three sensors, switch them out, PLUG THEM IN THEN HOOK THE BATTERY UP! If you dont do this, you can risk shocking the sensor and frying it. Turn the car on, let it run for a minute, if you still have the issue with it being in limp mode, adjust your tps a little bit so the idle is correct, then unhook your battery again for a minute to be safe then hook it up and check to see if it reset the ecu.
I did this on two cars now and it worked perfectly both times. The tps adjustment CAN send it into limp mode, but it probably wont, just start with it in the center of the slottled holes when you begin and it should be okay.
98-2000 Sensor Part Numbers, 2001-2005 have variances do your research!!!
89672-30020 - Throttle Control Motor
22060-46010 - Throttle Lever Assembly
89452-30150 - Throttle Position Sensor
And pictures so you know what they look like:
Throttle Control Motor
Throttle Lever Assembly