got a crx si header that ive port matched already, will it bolt up to the factory exaust until my catback comes in so im not without a car for days? its an hf model

 

depends... if thats a stock crx si header (4-1) then it'll fit. if its an aftermarket (4-2-1) it wont fit with a (4-1) downpipe.

 

its 4-2-1

 

It will fit and bolt right up to your catalytic converter. No mods, thi sis assuming its a D series 4-2-1 header. Mine needed no mods to fit. I have a 4-2-1 header, and a catback and nothing needed to be moded at all. And they did not go on together the same week.

 

my bad, never noticed about the HF system, that one I am not sure of.

 

yep it works i have an hf liek that right now. im using the stock exaust for now with the header so i have no cat. header bolted to the stock exaust no problem

 

You may need to get a test pipe, but it should fit. Since the cat on the stock HF was right on the manifold, you may be alright right off the bat, But when the exauhst does come in, expect to need to get a test pipe/ high flow cat.