First off ,welcome to the board

Second, the first thing you should do before post stuff on this board is use the search feature. Usually you can find your answer and some people get annoyed when the same question is posted by three different people.

Third, What about a free flow cat to match your I/H/E. That way you won't have any restrictions. I also agree that lowered springs and shocks are a good thing to do next. Also you didn't actually state if your civic was an Lx,Dx,or EX. If it is a an LX/Dx you can swap in An Ex intake manifold and get rid of that god aweful vertical Throttle body.

Fourth, the are some companies to stay away from like APC, matrix and more that i can't think of right now

Last, welcome to the board again


ronin