are resonators legal? this may be a dumb question. and do they replace the cat or connect to the cat?

 

well..if im thinking of the same thing your thinking off, its not connected to the cat, its a little down more, and if you take it out, it will make your exhust louder..so if you get cought with a loud muffler you could get in trouble for it..but it wont make it to lound, just add a little more buzz to it

 

the resonator is attached to the midpipe - usually. they're not illegal, almost the opposite.

 

It goes headers to cat, cat to resonator, resonator to muffler... no resonator means your civic will sound like a freaking tin can and no one will want to ride long distances with you... I say that because I have been experiencing this and I am sick of it! Luckily my 04 lx is such a dinky motor it really doesnt make much noise outside, inside is overwhelmingly loud.