chattering while steering in front

[09 lex 250]

hi all gettin ready for the bmax to hit some clay for the first time on sat! i cant wait! got a quick question.i was just doing some ecu tuning and noticed that when i turn the front wheels when the wheels are in motion im getting a bad vibration but when the wheels are straight everything is good.also when the wheels are off everything is good too.when i look at the wheels when they are on the car nothing seems to be rubbing. only when the wheels are on the car and i give it a little throttle is when i get the jumping and rattling. my wheels are properly balanced and glued. anyone have any ideas.other than that the car is ultra smooth and ready to run!!

thanks