You shouldn't have to take the bumper off. If you remove the wheel and pull back the plactic wheel well shroud and undo the corner of the plastic cover underneath then it should just unbolt and come right out. If you have a stock filter it will sound like crap. It will definitely be louder, but crappy loud, and you will not get a power gain. If you have a hi-flow filter like K&N, Accel, AFE etc. it will sound decent and give you some power. I would just say rip out the resonator and the stock air box and get a full intake. Then it will sound kick ass. If you get an intake, the longer the pipe is, the louder it will be.