why is the defouler needed

[mosi123]

I was seriously considering the vibrant raceheader with the HFC until reading a lot of posts about how you still need a defouler. Which this to me defeats the soul purpose of even having a race header with a cat.. If you throwing CEL's related to catalytic efficiency then why even bother throwing the extra money at a "HFC".. I say this because i doesnt matter when your getting emissions tested whether you have a cat or not if you have a CEL they are gonna turn you around and tell you to get it fixed before even finishing the test.. So why not just buy a raceheader with no cat and save the cash? It sounds like a great exhaust system, but makes me wonder how truthful a product can be if you are still getting CEL's with a HFC.. I've ran HFC's on other cars of mine in the past never having to worry bout a defouler/cheater/whatever you want to call it.. I need some clarification before i decide on which header to buy..

[NitrousG35]

Originally Posted by mosi123

I was seriously considering the vibrant raceheader with the HFC until reading a lot of posts about how you still need a defouler. Which this to me defeats the soul purpose of even having a race header with a cat.. If you throwing CEL's related to catalytic efficiency then why even bother throwing the extra money at a "HFC".. I say this because i doesnt matter when your getting emissions tested whether you have a cat or not if you have a CEL they are gonna turn you around and tell you to get it fixed before even finishing the test.. So why not just buy a raceheader with no cat and save the cash? It sounds like a great exhaust system, but makes me wonder how truthful a product can be if you are still getting CEL's with a HFC.. I've ran HFC's on other cars of mine in the past never having to worry bout a defouler/cheater/whatever you want to call it.. I need some clarification before i decide on which header to buy..

You may or may not need a defouler. Why take a chance? The Vibrant RH w/hfc will give you greater emission's compliance. Also a RH w/o a cat stinks to the high heavens. Have you ever smelled an Si w/o a cat? I have. They smell so obnoxiously bad, you have to cover your nose. In the summer, that smell could drift into your car at a stoplight. No thanks on that.

Not to be quibblesome, but this has been discussed at great length in many threads and posts. I created a thread about the install of my Vibrant RH w/hfc at length and there have been many people who have written about the benefits of a defouler. Also, the price gap between the two headers is insignificant.

There is a wealth of knowledge on this particular forum regarding headers, exhausts and defoulers. You will have to make up your own mind what you want. For me, having peace of mind regarding not worrying about a CEL, is more important to me than to be constantly fretting about getting a CEL.
I also like my systems to be as much like the factory as possible. That means a cat, albeit, high flow one. This will create less pollution and a more fragrant exhaust smell.

[Stealthcivic]

I just ordered my vibrant header w hfc and I agree with nitrousG35. I don't know whether to get the defouler or not. I wonder if I should get it on install or wait until to see If i get the CEL comin on? Anyway, I already ordered the Vibrant Header w/ hfc and can't wait to get it on.

[NitrousG35]

Originally Posted by Stealthcivic

I just ordered my vibrant header w hfc and I agree with nitrousG35. I don't know whether to get the defouler or not. I wonder if I should get it on install or wait until to see If i get the CEL comin on? Anyway, I already ordered the Vibrant Header w/ hfc and can't wait to get it on.

You can just go ahead and install the header. You may be just fine and never get a CEL. If you do, you can always get a defouler. Good news on that front as well because it looked like the source for angled defoulers had dried up. Now, several guys have posted links to sources and SCTuned said they will soon be carrying them. Just remember that if you do get a CEL, you will need to clear it out. Sometimes disconnecting the negative terminal work and other times, you will need a Scangauge to clear out the code.

[Mabuz]

Basically, the HFC option keeps you within the visual part of a smog check (along with keeping annoying smells down, as Nitrous said)...the defouler keeps your CEL from popping up to pass the remainder of a smog check.

If you don't need to pass a visual inspection, then go for the catless.

[mosi123]

Ok, great so you've passed the visual inspection side of it, its completely worhtless as i stated before to be able to do that if you have a CEL, or even one that has been "cleared" by disconnecting the battery.. But it will still be stored for a wonderful scantool or obd reader to see, now if you can get your hands on one and clear it that way then you'll be fine until the light pops again.. plus isnt this another reason we'd want a HFC is to not have to pretty much go through the same pain as if deleting the cat all together? So ya i agree you'll visually pass but unless there is a fuse (not sure if the 06+si's have this) to be pulled to completely clear the ecu's memory or you have have a scan tool to clear it.. we will still fail.. Oh and yes i ran with my svt focus for 3 years ya it you get more of an odor, did it kill me? no, as well as many of friends running no cats on many different makes and models.. As i did have a random tech HFC on my SVT before installing the long tubes and never threw a CEL until i went with not cat all together.. just doesnt seem right to me..

[Mabuz]

So, thats where the defouler comes in...keeps you from throwing a CEL.

[mosi123]

yes i know that it has the capability of completely passing, i guess i just dont like the fact of needing a defouler when there is a cat there that should do its job...

[Stealthcivic]

I guess I will go with the header without the defouler at first, and then get one if i get CEL....thanks for the tip,
to the OP, bro the header is the best mod for your si, gettin a header and reflash is the best mod you can do now n/a hands down...do your own research on here and ask others that have done mods....in reference to your concern, like mattsboro says...he doubts the header w/ hfc will pass emissions!! This is why the CEL light comes on because it is reading emissions trouble....I don't care my state has no inspections, but like Nitrous, I don't want my si smelling like gas all the time, and being super loud, this is why I went with the header w/ cat....I also am in the surfrider foundation and we clean up and care about the environment...hehe
So, if you are concerned about passing emissions, I would question even getting the header w/ hfc, or you have to take it off and put stock back on at inspection which to me is a pain in the A$$! I am not switching anything back and forth....I hope you understand the header w/ cat might not pass emissions, they vendors say it will just to sell the product. They don't know for sure. Talk to someone that went through inspection with the header w/ cat is the only way to know . Good luck...

[Mabuz]

Well the Vibrant page states "for offroad use only" so there is nothing saying it is guaranteed to not throw a CEL.

[mosi123]

My state has no emissions testing either, but i would like to keep the cat if possible. Though im not apposed not having one seeing as im running buddy club right now..apparently this cat does not do it's job as if it were we would not have CEL's and there would not be a need for the defouler making it pretty much worthless to me then. I was just hoping there maybe RH with a cat. That worked properly I could pick up, but looks like I'm keeping my BCRH..

[vtecmike1]

i havent thrown a cell and i have one. over 1k+ miles.
its diff for everyone i guess. but i'd say get the header on and if you throw a cell then get a defouler. no sense in spending money if you dont have to.
don't throw a cell.. dont get a defouler
simple as that.

[NitrousG35]

Originally Posted by vtecmike1

i havent thrown a cell and i have one. over 1k+ miles.
its diff for everyone i guess. but i'd say get the header on and if you throw a cell then get a defouler. no sense in spending money if you dont have to.
don't throw a cell.. dont get a defouler
simple as that.

Well said. I think some of us have made it very clear to the OP regarding the rationale for using a defouler. As I have repeatedly said, I want something that at least has the semblance of a cat for a visual inspection, plus something that will have a catalytic effect on the exhaust gases. The price gap for the Vibrant RH w/hfc is marginally more than the non-cat version.

Having a RH w/hfc will also smell a whole lot better. I was at a meet last summer where one of the guys had a DCSports RH. There was no cat. The smell to say the least was vile. A plain RH also creates a lot more pollution. Why dirty up our environment any more than we have to?

The defouler is a small price to pay for total peace of mind. It has nothing to do with the effects of a Vibrant RH w/hfc. Having the defouler will keep me from having to clear out any CEL's. I will go the extra mile to make sure that doesn't happen. The defouler in no way defeats the purpose of the Vibrant RH w/hfc. OP has been informed. He should go with what he feels is right.