What is wrong with my steering?

My Toyota Sienna pulls to the right horribly. This is a 2000 model. After new tires, a new steering pump, a new rack and pinion, and 4 wheel alignment this thing still tries to drive off the road. I talked to the Toyota dealership, they said it does have a steering angle sensor, but also said that it would not cause the car to pull even if it were faulty. What else can it be?:banghead:

have they checked the wheel bearings? could also be a brake caliper hanging up

Crvett69: I know they checked the brakes, not sure about the bearings though. Thanks for the suggestions, I will let you know what I find out!