If you're running the stock Lexus ECU with your 1UZ, it's pretty much a sealed black box, and there's not much tuning that can be done (by most mortals).
If you have all the original sensors still hooked up, it'll start learning and tuning itself based on temperature, pressure, and lambda sensor feedback, as soon as the engine starts and is running.
It would be a good idea to have a knowledgeable Toyota technician handy just to help troubleshoot any teething problems that crop up.