so ive been playing with the idea of getting the cutout which qtp sells.. but ive been thinking about it and been wondering if i decide to run this i would have my stock cat and maybe just my hks carbon ti catback on.. if say i wanted to run with the downpipe fully opened would this make me throw a code (po3000 i believe "o2 sensor") since all the exhaust gases are leaving via the cutout before the o2 sensor making the second o2 sensor by the cat not read the correct gases and throw the code.. thanks for the advice ahead of time

 

I don't believe so, as the code should only trip when the gas exceeds stock cat levels. If you are below stock levels (ie, no gas hitting it), it should report all OK