I want the A pexi gt spec exhaust on my 92 Civic hatch DX. Now my question is the down pipe i think is 3 inches Now will that bolt up to my stock catalitc converter or will have to replace it with a larger one. and if i replace that will that bolt up to my headers on my D series motor Im not really sure can i get some help. Thanks.

 

You already asked this.
The answer is still: Think about about it...you really should be able to answer this yourself.
Stock size is not 3" - meaning you will need to flare the cat's flange to that size, or change the entire exhaust to that diameter. If youre only planning on a 3" dp and 2.x" piping behind that, youre not gaining anything but monetary loss and backpressure further down the line.
3" is ridiculously large for n/a hondas

 

3" exhaust is adequate for high boost applications. otherwise stick to 2.25" if ur n/a.

 

My apexi gt spec is a 2.5 inch pipe