I maybe wrong here, but if oil is present in the pipe and breather, it maybe an idea to remove your crossover pipe and check its free of oil. If its not, you will find that oil has found its way into your intercooler, which isnt good. Parts affected would be the throttle housing, crossover pipe, joining hoses (throttle and boost) and intercooler.

If oil has got its way all round those parts, clean everything and it would be advisable to replace the little breather unit. It only costs pennies to replace and will no doubt help solve future problems.