kinvid22

i'm trying to find a cat for my legal exhaust set up for my d-series motor. i know the flanges on the b-series header and exhaust piping is a tad wider than the d-series, but does it apply to the cat too?

i've heard the 99up civic si cat is the same as the 96up civic ex, can anybody confirm this?

I know for a fact that a b-series header does not match with a dx exhaust because the flange size is different and bolt holes doesn't match up? I tried putting a type r header with a brand new apex exhaust that is made for 96-00 hatch on mines. I end up hacking a gsr cat flange to weld it on my dx piping so it will bolt up to my type r header. I regret doing that to a perfectly working gsr cat.

if the two are the same, how would d-series cat (96up EX) match up with a b-series header(99up SI) ?? TIA

ssbpturbohatch

i know on my eg hatch i've had a cat from d16z6, 99 b16a, and now a straight pipe from 99 ex, it doesnt always work the same for everyone but that is how mine is

EVIL Hx Coupe

I replaced my stock exhaust (1996 HX) with a 1999 Si full Bpipe and cat and it bolted right up, the flange matched perfect to the header.

WildPig

I have a 00 civic hatch too and recently got a dc sports civic ex header for it. I ended up buying a 99 si cat from someguy on HT and it bolted right up to the headers but not to my apexi n1 exhaust. I took it to a muffler shop and they just chopped one of the pipes and welded on a universal flange that fit. Everythings cool except I need a gasket that fits the dc header to the ex cat.

Do you know what gasket will fit? And yes the 96-00 ex cat is the same as an 99-00 si one, I'm pretty sure that they are even the same part numbers from honda.

EVIL Hx Coupe

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by WildPig &raquo;</TD></TR><TR><TD CLASS="quote">I have a 00 civic hatch too and recently got a dc sports civic ex header for it. I ended up buying a 99 si cat from someguy on HT and it bolted right up to the headers but not to my apexi n1 exhaust. I took it to a muffler shop and they just chopped one of the pipes and welded on a universal flange that fit. Everythings cool except I need a gasket that fits the dc header to the ex cat.

Do you know what gasket will fit? And yes the 96-00 ex cat is the same as an 99-00 si one, I'm pretty sure that they are even the same part numbers from honda.</TD></TR></TABLE>

You need a doughnut gasket for a 99-00 Si or 96-00 Ex, they're both the same. You can pick it up from your local honda dealership.

kinvid22

i always wonder how would a b-series header from the 99up SI flange match up to the d-series 96up EX cat if my type r header flange was a tad bigger than a d-series DX flange?

EVIL Hx Coupe

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kinvid &raquo;</TD></TR><TR><TD CLASS="quote">i always wonder how would a b-series header from the 99up SI flange match up to the d-series 96up EX cat if my type r header flange was a tad bigger than a d-series DX flange?</TD></TR></TABLE>

You're talking SI and type R... Si header has a smaller collector than the type R, that's why the Si cat fits the D series headers.

kinvid22

donut gasket is key...

to fit b-series header to d-series cat, you need to put a d-series donut gasket to your b-series header.

96up EX cat the same as 99up SI, confirmed

thanks

WildPig

Ok i definately tried though, the collector pipe on the dc sports header is bigger than the stock one and my gasket doesnt fit over it.

Can someone give me a little more info or tell me what I'm doing wrong? I hear that a integra gsr header to cat gasket will work, but maybe im just an idiot. Thanks.

b 1 6 a 2

The oem header on my b16 fits directly into the D series cat. I believed I switch the donut gasket, but dont remember.

99-00 si should have the same cat as 96-00 Civic Ex's.

What can I get for a used cat no a days? I have an extra laying around from a 99-00 SI.

Marauder

99-00 Si cat is the same as a 99-00 EX. The 96-98 civics have a different O2 sensor placement.

b 1 6 a 2

Cool, thanks for clearing that up. I didnt want to sell my cat and claim that it fits 96-98 ex's too.