I want to put a cobb tunning stage 2 kit on my 2000 Impreza 2.5 Auto and it is asking about the cats. When it comes to the equal lenth headers the option is a race pipe or stainless steel catback. Should I say yes or no when answering thre cat question and what is the way to get through the emissions I live in Maryland. They pug into your ECU

Thanks DDAY