that K&N, short ram or cold air?
i've been running the injen sp1204 cai without a tune for awhile. no CELs. car feels great.
:but ZOMG your AFR, you're engine's gonna blow uP!: ya blah blah blah. my AFR is fine. 08+ wrx's switched it up to the legacy airbox setup as opposed to the 02-07 wrx's