I am about to change wheels and tires and expect the same issue (if TPS guages do not transfer to new wheels). I found a discussion on this other forum: http://www.clublexus.com/forums/forumdisplay.php?f=63
Best fix appears to be:
- put shifter on N, screw off shifter
- open up center console
- pull the whole heated seat module straight up, it will come up. disconnect
- you will be able to pull up the "back" part of the shift plate area (close to center console)
- once it's up, the only point holding it are two clips right below the radio
- pull the shift plate towards the back of the car and a bit angle up. jiggle a bit and it will come off
- once it's out, you will see the TPS unit right below the radio
- unplug BOTH plugs, one small on the right and one bigger one on the left
- put everything back and enjoy
but don't know if I will be brave enough to do all that.