bro on my 2008 bmw 328i V6 i deleted the Primary and secondary cats also deleted the resonator and muffler it sounded INSANE that i was already dramatic on just taking off lol and i lost back pressure so i got a dope resonator put on that’s meant for a fully straight piped cars also i got a cutout valve to open and close the exhaust and boy i can still be insanely loud when ever the valve is fully open without it being too loud when you on only 2,000 RPM it’s the best thing i’ve done too that car i can say i’m fully straight piped from the front too all the way back
