Pablo,
I am having the some exact problem with my Rx300(2001). In addition to feeling like the ABS was kicking in the VSC (vechilce skid control???) light on the dashboard flashes along with a light showing a vechicle with small skid marks. Currently the CEL and VSC are illuminated on the dashboard, but the car drives normal and I have not been able to dublicate the problem for a few weeks.
I took the car to a local mechanic and pulled the following codes:
C0200- Right Front Wheel Speed Signal Fault
C1223- Fault in ABS Control System
C1224- Open/Short Circuit in NE Signal Circuit
P1130- A/F Sensor Circuit Range/Performance B1-S1
I am wondering if you can share any details on how to correct the problem? I am planning to change the ABS sensor tomorrow which is $200, unless someone knows how to get cheaper?