im thinking of doing an exhaust with the valve that opens up to make the exhaust come right out of the header (theres an ongoing thread already about this product), i plan on mounting this piece after the header and then the cat after that. Im worried as soon as a open that valve up the o2 sensor light is gunna come up. Is there any trick i can use to stop the 02 sensor from triggering? I know there was things people did to there tc's but im courious about the xbs.