wich should i ge a test pip or a high flow cat wit 2.5' headr
back to apexi N1 exaust?

If you are not boosted or sprayed a test pipe is going to kill
you performance. You MUST have back pressure with a NT/NA
vehicle. In either case, I would have to say hi flow cat.
There is a reason that you have a cat on your car. If you
don't car about mother nature or people behind you (test pipes
smell horrid) then go for the test pipe (35 bucks most
places), otherwise go legal and use a street legal hiflow cat.
Remember, just because you might not have emissions in your
state does not mean that you can rip the sons of bitches off.
Just food for thought. Peace.

Trevis

 I went test pipe with my car I got a header and muffler. Duno
what is better but I would think that the muffler on the cat
back would give ya enough back pressure. I might be wrong I
think alot of guys run test pipe.