si-thee

i had a td05 20g fitted to my 06 sti and found that car was using more oil than before and was told from quite a few people that the engine breathes a little heavier with the 20g, so i fitted a catch tank to crank breather and have been running for a month or so with it. i have kept an eye on it since fitting it and not had a drop of oil in tank but have needed to top up oil not by much though.
so now im puzzled anyone having same issue or any ideas

cheers