[i30_NL]

I have an i30 N-Line and recently installed a race pipe (which is essentially a 2nd cat and resonator delete) and new exhaust system with two straight-through, round-body growl mufflers.

I've noticed when the revs hold at 2000rpm it drones quite significantly.
On the motorway etc there's nothing which is good.
Does anyone have a suggestion to reduce this or is the only solution to re-install the resonator?