MY03 is driving me up the wall at the moment, It has full HKS coilovers fitted but recently its start knocking both four corners even the small bump on the road which i dont think this has anything to do with the way the suspension has been set up. Any idea what could cause this knocking issue? Any help would be much appreciated.

cheers

 

most coilovers knock over bumps etc, its mainly because there so hard. i used to get it alot with some fk's. not the same league but it could be the same problem.

 

As above, alot fit new fancy 'coilovers' to cure the sti's knocking. But a while later its back.
Check the helper spring and its preload.