Evo 4 Oil Light Problem

[jdmsport]

My oil light is flickering when car goes below 1000rpm

I have fitted a new oil switch,new oil pump,new oil & filter but i still have the same problem.Also cleaned the sump and pickup out which did have some bronze type metal flaking in it but car has possibly had a blown turbo at some point and they have came down the return

This is doing my head in anyone have any idea ?

Thanks