when i got my honda I removed all exhaust parts. Now all I have is headers and a pipe going from the headers to the muffler tip... Will a high flow Catalytic Converter reduce some of the noise and help with some of my back-pressure

 

it'll probably help a little. You can also look at getting a resonator, that'll help as well. You could also switch to a cambered style muffler rather than a straight through if thats what you have.

 

Why didn't you just say you're running straight pipe? Get a muffler...that would help

 

yeah, get a muffler yo maybe a hollowed out muffler even, ive ran my car on just the cat and stock resonator it sounds good

(i was painting the muffler, it was ugly and spotted )