Should I remove the resonator AND the cat?

[BwolfGT]

yeah i was def. planning on the FWI and 180* t-stat...but i heard that aside from the super-power-awesomeness spawned from the FWI, it actually lowers your mpg?!?! is that true?

No. It will most likely remain unchanged, some people actually see very minor GAINS in mpg, but that's about it.