i have a 99 dx and i plan on putting a b16 in later.. i want to get the exhaust system done first.. since the factory header has the cat built in, can i get an ex header/cat/exhaust on there? i know the o2 sensor is right up front, can i get this wire, #26 in the pic, so i don't have to extend the o2 sensor over there?

 

#26 is a 2ndary sensor wire not sure if it will work. There is a company that makes o2 sensor extension wire

 

when you get your b16 you are gonna have to extend the 2nd o2 and run it straight to the ecu. if not you can run straight pipe. the b16 header will match up with the exhaust with no cat. might have to cut the flange and turn it. to make it fit right.