i see, well i had a k-tec sports cat on my 172 cup never had any problems with the warning lights, passed mot fine.
Its not really the "having to change it". im a very picky person and everything has got to be perfect, so if the warning light came on it would end up annoying the hell outta me lol
Say performance wise, how much better is a de-cat pipe compared to a sports-cat?
ill probably go for a YS de-cat based on the fact that my funds are quite limited at the mo