dont bang it out. it will resonate terribly and create that bumble sound thats super annoying.

also having no cat is basically making your car equal to 50-60 other integras with operating catalytic converters.

but if u truly do crave the extra 1-2hp that you may gain, going with the test pipe is ur best bet. no funky bumble bee resonance and lingering fumes.

also, since you have a 99, you're going to throw a check engine light because the secondary o2 sensor will detect that the same measurement as the primary sensor. its not supposed to be the same.