I am running dc headers, test pipe, and an invidia cat back. Is this not enough back pressure? I have always owned turbo cars so the less back pressure the better. I have an NA b16 so would it run better with a cat rather than just 2.5 in piping?

 

Hondas cats flow very well you might see 1 HP if that.

 

I just have a test pipe on it right now. I was wondering if I should put the cat converter back on it.

 

I would say yes.
Less smog and it's not going to hurt you.

 

I'd leave it out. I've never run one in any of my cars except one or two. If there's no difference why bother putting it back in. If you end up doing some more mods in the future it may become more and more beneficial to have that catalyst removed.

Just my opinion.