Hi theres a rattle coming from my toyota yaris's driveshaft or steereing rack ever since i had a bang i? help?

i had a bang in my 99 toyota yaris, i fixed it as it was jst exterior damage and had it mot'd after everything fine! but ever since theres been this rattle coming from maybe the driveshaft or steering rack :s not sure sounds like its passenger side? it doesnt happen wen im not in gear but it follows the revs of the engine? also it doess not happen when im steering right ?? any help please??