Three places on the rack for adjustment, the rack ends, which are a bit of a pain to dismantle as they are 'pinned' at the factory, not really likely to be them, but check them to see they are 'tight' on rack end threads especially if the rack was shortened to correct bump steer, not everyone puts em back together as good as the factory did on day one!
Rack Pinion- end play adjustable by shims under cover with either two or three bolts on 'front' end of pinion.
Rack to pinion pre-load- again adjustable by shims under a similar 'top' cover.
Easier to do this on a bench, & be aware that the pinion/rack can get extra wear on the 'straight ahead ' position particularly if it was a S/H donor rack.