I have a '98 Limited, and i really hated the chirp when i used the keyfob, and i searched online for the security system that came on the 4runners in '98 (im not sure about 97), and i found out that it was a Toyota VIP RS3000. I searched google for a Owners Guide, and it was a PDF file, and i printed it. I no longer have the link that i used to get it, but in the Owners Guide, it told how to use every part of the security system. It was very easy to turn off the chirp, and it tells how to put it in Valet Mode, which makes it so that the key fob only locks and unlocks the doors. To turn off the "PIEZO chirper", follow these steps (i know they work for my 98):
Step 1 - Insert key into the ignition switch, and turn it to "ON" (not "ACC")
Step 2 - Using 1 remote control, press and hold BOTH buttons (at the same time) for over 2 seconds, untill the Status Monitor's LED turns on.
(you must perform the next steps within 30 seconds)
Step 3 - Press and release the BOTTOM remote control button ONCE (the PIEZO "Chirper" chirps ocne and the exterior lights flash once)
Step 4 - Turn the ignition switch to the "LOCK" postion (the PIEZO "Chirper" chirps 3 times, adn the exterior lights flash 3 times)
This should make the Chirp stop, and if you decide that you want the chirp back, follow the same steps, but in Step 3, press the bottom button TWICE
Hope this helped
-Billy