Im thinking about putting a test pipe on my stock exhaust and take the cat off is it a big dif?
dose it sound diffrent better or worse?
will it smoke if the test pipe has the hole for the o2 sensior?
And how much more hp will i get with just the test pipe?

 

It sounds deeper and not raspy, u will smell the exhaust more and u can gain a few hp, i gained a few mph in the 1/4 mile with mine.

 

so its much louder with the test pipe but stock exhaust? can you feel the dif? and will it smoke?

 

It wont smoke at all! I went from trapping 97-98 to 101mph at the track so u should feel so response on the street.

 

dose it matter on the brand or i can get any test pipe and it should be the same?
how dose it sound?

 

I had invidia the 2.5 inch! Then i had the 70mm version.

 

2.5 and 70mm are both thicker then your stock exhaust how did you put it on?

 

If you buy TP for s2000 all flanges/bolt patterns are the same no matter what pipe diameter is. for stock exhaust get some 2.5inch(63mm) and you are good to go.

 

only thing im worried about is the sound how will it sound? or since i have stock exhaust should sound stock?

 

it sounds slightly deeper and louder. not a huge difference. it will def sound stock still.

you cant leave the o2 sensor hole open because you will need to put the o2 sensor there so you dont get a CEL.

I recommend the Berk 63mm, it works great for my exhaust. its only like 100 bucks so try it out and if it doesnt work, sell it. lots of people are willing to spend 100 bucks on a used Berk TP.