i was wondering if this will fit my 91 crx si with a d16a6 engine? the dude selling it said it will fit any d series sohc. is that true?

 

The header will bolt up to your head, yes. The only thing you might/should be concerned about is if that header fits in the engine compartment.

 

you may need to use a 92-95 civic half rad

 

It should be fine, I've personally ran several different varieties of "92-00" civic headers on my EF's without any complications. 2-piece FTW though, those 1-piece ones suck because you have to drop the front X-member to get them on and off usually.

 

You will need to extend the wires for your O2 sensor.It might not read as well that far from the head, (I'm not sure, I've heard it both ways).

 

What about it bolting to the exhaust? I have a 90 Si and I went to replace my header, I think it was from a dual point, well it was about a foot from the exhaust when bolted up.

 

Missing catalitic convertor?

 

No, the cat was still attatched to the exhaust... Like I said, maybe because it was the lowly dx or std that I got it from?