I bought two keys on EBay ($36), and down loaded the procedures.
i got the two new keys cut by Lexus for $25 each, no locksmith would help, gone the way of the pay phone I guess,
The first procedure for registering the ignition key transponder to start the car went smoothly, the key fob procedure required a little tweak.
Then I moved on to the procedure for the remote lock function for the key fob.
apparently there was a small tweak necessary in the procedure.
below please find my edited procedure for both. Hope this works better for everybody with a 98 LS400.
LEXUS KEY PROGRAMMING (to allow starting engine)
Requires one working LEXUS Master Key.
1. Enter the car with the existing master key and close all doors.
2. Simultaneously depress and release both the brake and the accelerator pedals.
3. Within 5 seconds, insert the existing master key into the ignition. DO NOT TURN THE
KEY.
4. Within 15 seconds of inserting the ignition key, depress and release the accelerator pedal
5 times.
5. Within 20 seconds, depress and release the brake pedal 6 times and…
6. Remove the existing master key from the ignition.
7. Within 10 seconds, insert the new key into the ignition.
8. Depress and release the accelerator pedal one time. The security light will soon begin
flashing to indicate that the computer is reading the new key and programming the
system.
9. Leave the new key in the ignition until light stops flashing (might take up to 80 seconds).
When the security light stops flashing the new key is registered
10. Remove new key and depress and release brake pedal 1 time.
The programming process should be complete.
Test the new key. Place the key into the ignition and verify that the car will start.
If this is a new remote master key, test the remote functions on the new key.
Remote Programming Instructions (to allow remote lock/unlock/trunk)
1. Driver's door OPEN and unlocked, all other doors closed and locked.
2. Insert YOUR key in ignition, DO NOT TURN, remove key.
3. Using the MANUAL lock/unlock button ON THE DRIVERS DOOR, slowly press lock and unlock 5 times (count the lock 5 times and unlock 5 times).
4. Shut door.
5. Open door.
6. Using the Same Manual lock/unlock button ON THE DRIVERS DOOR as above, slowly press lock and unlock 5 times (count the lock 5 times and unlock 5 times).
7. With the door open insert your key into the ignition, turn to on position (DON'T START), wait ~1 seconds. Turn off and remove key.
8. Locks should cycle once (Car will lock and then unlock once). If they don't cycle or they cycle more than once, do steps 1-7 over.
9. Now using the remote, push lock button (EDIT) and the unlock button simultaneously, hold for at least one second, release, then push one or the other (lock or unlock) and hold for at least one second. At this point you should hear a long sustained beep, while the security light is on. This should be the indication that you’ve successfully programmed the key fob.
The locks should cycle once. If not, start over and go slower.
10. Close the door. Open the door. Press the lock button on the remote.
The locks should cycle. Close the door. Press the lock button on the remote, the doors should lock. Press again and the doors should unlock.