I've noticed a problem on my 99 TL. When I'm a low speeds 5- 10 kmph and I make sharp turns and I feel like something is loose, like on one of the front wheels. It feels like the wheel catches and then gives. I notice it more when I turn left. I've been to the dealer 3 times to have this verified along with other things and they haven't been able to tell me what's wrong. The bearing was changed on the front driver's side wheel, and both ball joints have been changed, as well as both link kits, but I still feel the problem. The mechanic at the dealer noticed the problem during a test drive, but after checking my suspension and bearing and whole front end, found nothing wrong with my car. He now tells me that it is because of my tires. My car is completely stock except for my tires, which I have oversized to 225/55r16 Toyo Proxes 4. (I know it may be sacreligious to have a bone stock TL but hey I've got 2 kids and a third on the way...I have no money left.) The mechanic believes that due to the oversize tires that my powersteering is straining a little more and due to the extra resistance causing the loose feeling in my steering. He tried putting on 205/55r16 in the front to see if the problem would go away. HE claims it did, but when I tried the car it seemed like the problem was still there, although it was less detectable.
Should I be satisfied with this explanation, or did he just say that because he is stumped and has no other explanation.
I would appreciate any expert advice!!!

 

if after replacing all that all i could think of would be the PS rack maybe causing it?? tires shouldnt

 

Mechanic said that there were no leaks and that eveything seemed fine with the PS. Also there is a small vibration at hwy speeds 110kph (70mph). Mechanic told me he didn't feel anything during test drive. I felt it today on my way to work. It's not huge but definately there. I'm not quite sure what to believe.