Alright, I'm trying to figure out what header to run, since I have a huge exhaust leak in my stock header.. What size outlet should I run? Is B18A/B header the same as B16? What year integra/del sol, etc. should the header come from? Do I need to use the 2nd O2 sensor? How do you do about extending the 02 sensor since most of the bungs are at the cat on after market exhaust? Will a 90-91 Integra header remove my cat, since it looks longer in the pictures? Any help is much appreciated! I need all the help I can get, my stock header is pissing me off.