95 GSR B20VTEC

My stock 97 DX header (header with the cat attached) is cracked down one of the runners. Since these are generally expensive and hard to find, I was wondering if I could replace my stock DX header with an EX header & cat without having to change the stock exhaust? My logic tells me this would work just fine, but I wanted to see if someone could clarify this for me. Any tips are helpful, Thanks guys.




Modified by 95 GSR B20VTEC at 3:36 PM 10/26/2008

hosv

Yes, youcan, I did the same.

Im using the ex manifold without Cat in my Dx.

Good luck.

Silvertc

iTrader: (1)

95 GSR B20VTEC

Awesome, thanks for the info!
My question is, you say youre using it with no cat? Do you have something in place of the cat? Could you run a cat if you wanted to? Thanks!

jimmy o.

yes the piping is exactly the same you can retain your cat if you want the guy about is probalby using a test pipe which is an option

95 GSR B20VTEC

thats exactly the answer i was looking for. thanks so much!

jimmy o.

mo problem

TheJGB3

Here is the parts exploded view for the hatch and EX/Si
DX/CX exhaust


EX/Si and 4door models


So it looks like hosv is running his old extension pipe #9 (1st pic) without a cat. If you want to run a cat then you will need the EX/Si extension pipe #18 (2nd pic).


Modified by TheJGB3 at 11:45 PM 10/26/2008

95 GSR B20VTEC

anyone tell me how i can get around the CEL when swapping headers?

hayes

are you buying an oem ex header?

95 GSR B20VTEC

yep

EL Vap133

The only problem I see you having is what are you going to do with the other o2 sensor? The EX manifold has only one o2 sensor bunghole.

95 GSR B20VTEC

thats exactly what im wondering :]
i know its not uncommon for people to put y8 headers on their y7's. so what do people usually do to remedy this?

EL Vap133

If you can get the 96-97 EX manifold with the #9 extension you will have a bunghole for both o2 sensors. Not sure if that will make a CEL go on though.

95 GSR B20VTEC

thats what i have... thanks el vap.
im hoping it wont. i guess theres only one way to find out.

anyone else done the DX to EX header/exhaust manifold swap sucessfully with no CELs?

EL Vap133

Ok good, cause the 99-00 Exhaust manifold doesn't have the o2 sensor bunghole on the manifold.

95 GSR B20VTEC

Thank you, i didnt know that previously. Luckily It looks like i have the 96-98 and have 2 o2 bungs. So I think I may be in luck.

The_Honda_Guy

This is one of the things I had been researching too. If you don't plan on using a cat you'll obviously be throwing a CEL. The problem is that without a cat you'll always be getting a catalyst efficiency code unless you get an O2 simulator (I believe that is the name). My plan was to completely swap to an EX exhaust using exhaust parts made for a EX. Apparently the EX exhaust uses the same hangers as the DX, just that the manifolds and cats are setup differently. You can use the DX catback on the EX, but you'd need a length of pipe to gap the open space left by using the EX manifold IIRC.

Import_spoon

You just need the O2 sensor closes to the head. I used to have a Y7 and I did header on it. I used the top O2 but the bottom one I plugged it and no CEL. Try it for yourself and let me know.

silentone

iTrader: (1)

you could also just let your second o2 sensor be plugged in and hang it somewhere. i just zip tied it somewhere safe in the engine bay. all it really does is see if your cat is working efficiently and if it doesnt read anything bad, then it wont throw you a code. thats what i did when i had no place for it.

95 GSR B20VTEC

awesome, thanks for the input guys, much appreciated.
gonna give it a shot tomorrow.