You are describing the classic symptoms of worn steering / suspension parts...
Remember that the height of the car affects the steering settings.... that is why I suggested the new springs " as a matter of principle" as the FSM says so often....
Springs have a much shorter ' life span' than most people think.... I am not going to post it because I will get a bunch of flack... but the height your car is supposed to be is listed in the FSM... so you can measure it... it all has to be right to have any chance of the toe in staying correct during all the things a suspension needs to do....