the OEM tips are installed in the car to the glass packs, they just put the glass packs in place of the OEM exhaust.
So, If I plan on installing a less restrictive intake (probably just a K&N filter) and put the OEM exhaust back on, should I still do the glass pack / resonator swap? or is it useless to do that? I dont want to lose MPG really. I dont plan on racing the car in any way, so my performance upgrades will be based on the practical side.