I have the dc jdm 4-1, sms cat, and some POS exhaust I got this summer before I knew what the hell I was doing (it says hayame on it and has some kanji, I've never heard of it though). Anyways I'm sick of my car smelling like a semi truck when I'm at a stop + the check engine light, and I'm also REALLY sick of my loud POS catback. I would just get a different exhaust, but I don't really want to spend money on a nice performance one and I am sick of police harrassment so I want to go back to stock (except for the header which they can't see).

now my question is, would there be any problem bolting up my stock cat and catback to me dc jdm 4-1? how about my sms cat to stock exhaust? yes I realize I will be creating a bottleneck, but really, the header is the only thing that gives any serious power for bolt ons, and the stock exhaust is nice and quiet, and I'm not planning on doing any serious engine work for a while, if ever. thanks guys!

 

Your stock cat will not boltup to the jdm dc.

If you get the right carsound cat it will all bolt up.

 

You CAN run a DC JDM 4-1 with an SMSP/Caround Cat, and it will bolt up to the stock exhaust.

You CANNOT run a DC JDM 4-1 with a stock cat. Won't bolt up due to the increased Diameter.

I'd IM SMSP about the correct cat for your application.

Before I got my exhaust, I ran a dc jdm 4-1 with a carsound cat, bolted up to the stock exhaust. worked great.

 

Use the header, SMSP cat., and stock B-pipe, but remove the first bottleneck at the cat./B-pipe flange with a 2.5"-> 2.25" tapered reducer.

 

ok thanks guys, I guess I'll have to keep using the sms carsound I've got. gotta love CEL

where can I get the tapered reducer?


[Modified by 2000R#1355, 11:48 AM 3/17/2003]

 

"any" carsound cat will bolt up.... if the muffler shop makes the right flanges.

as referenced in my thread below, you can get the canister style (53006) or oval style (93066) carsound cat, and it will be universal. you'll need to go to an exhaust shop that can make flanges for your jdm dc 4-1 (2.5") and for your stock catback.

or you can call SMSP and he'll make one with all proper flanges that will bolt right on.

https://honda-tech.com/zerothread?id=445284

EDIT: dang you guys are fast!! 3 posts while i was writing mine...



[Modified by ajchen, 7:48 PM 3/17/2003]

 

I'm not sure which cat I have. I got it as part of the deal from the guy I bought the dc jdm 4-1 from. hopefully my mechanic can make it work.

 

if you take it to an exhaust shop they can pretty much make anything work...

 

Well, you keep referring to it as an SMS cat., in which case it should already be the proper length and have the proper flanges. The reducer can be purchased from Dave as well, in either stainless or mild steel.

 

You must type 5 words a minute!

 

yes it is a sms cat, but I was looking at ajchen's post and he was talking about two different kinds.

anyways do you recommend the mild steel or stainless? my dc jdm 4-1 is ss if that matters (which it probably doesn't). how much is the tapered reducer? will it make my stock exhaust louder or make a difference for passing smog? I'm in CA so I already know I'll have to go back to stock when I need to pass smog again, just don't want to screw up the exhaust at all. thanks!

 

I would recommend SS if you can. It will last longer.

The tapered reducer does not cost that much.

You will not pass smog, visual, in CA for having the jdm dc.

 

I already know I'll fail due to my header, question is will doing the taper on the exhaust create any further problems passing smog? I'm assuming probably not but just want to make sure.

 

No it will not.

 

I doubt the taper will cause more of a problem with inspections.

I 'think' the reducer/tapered flange is $55 or so from SMSP. there is an old thread about it out there somewhere... I'll try to dig it up.

https://honda-tech.com/zerothread?id=204632

 

SMS only uses the oval 94 series, so thats probably what you have.

please do get the SS one... seen too many CC's crack and rust.

 

modify your stock cat
or lengthen a test pipe


[Modified by itr-j, 12:18 PM 3/17/2003]

 

Dave now uses different ones rather than the 94 series.

 

he uses the 93506 now, which is almost the same layout. i just said 94 series for simpliticy's sake, and it does still work.

 

I believe ajchen was talking about universal Carsounds, not the ones that Dave sells. If you are concerned about returning to stock and not altering the exhaust at all, then the reducer isn't for you, since it requires removal of the stock flange and welding-in of the reducer. However, since the flange on the reducer has the same bolt pattern as the stock flange, you should be able to bolt the stock cat. to the reducer if you ever need too. Either way, the reducer shouldn't affect your passing smog, but it may slightly alter the sound since there is no longer the turbulence caused by the mis-matched flanges.

 

I don't mind altering my exhaust as long as I'll still pass smog and everything stock will still bolt up. thanks for all the help guys!

 

If you have a muffler shop do your work, make sure you tell them that otherwise they might weld ish together and it will get messy.