i just got a header for my 94 325is and i heard that you have to do without the cats, is that true? what am i supposed to get to replace them? could i just go straight pipes from my header back, and have no o2 sensor? do you absolutely need the o2 sensor? how many o2 sensor(s) do i have? how long does installation of a header take? will someone who has knowledge of modding bmw's explain this all to me?
im bolting on a 95 m3 exhaust at the same time, if that has anything to do with the questions
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mods: intake, m3 exhaust, chip, carbon fiber hood and emblems, clear corners, reverse indiglo gauges
stereo: panasonic touch screen, polk component set in q logic kick panels, kicker 5 channel amp, 12" kicker square