Aftermarket Header To Stock Cat

Hey fella's, haven't found a concrete answer on this yet so I figured I'd ask.

I've currently got a 97 EK1, D16Y4 with a short ram. I'm looking to do the exhaust next and with my current monetary situation I can only afford bits at a time. So I was looking into throwing an Ebay 4-2-1 header on just for the hell of it. My first car being modified, don't care much for price or quality just doing it to get the know how for later endeavors.

The problem is, the particular set I'm looking at says direct bolt onto stock system, however I'm slightly worried about it connecting to the stock cat. Would I have to purchase another cat? Or would the headers bolt on without the need for that?

Cheers in advance.

Have you got a link to the header you wish to buy? TIm assuming theyre street headers. Race headers are usually cat less and have additional piping in the cats place.
Be wary of aftermarket parts, are they reputable like Mugen or toda? cause regardless of what maunfacturers say most of them are not a straight fit believe me, this is for all parts. Who ever does your header installation should be able to whip something up to connect the headers and cat if it is not a straight fit. But if I was you, I'd rather save for the whole thing then put it in so out dont lose out on time and money on labour.

Cause even if you have a nice high flowing header, the stock cat and cat back are restrictive.

Wait longer save longer do it all at once be happy all at once and save alot on labour unless you can DIY

I recommend doing it all at once.

N*Power 4-2-1 header from ebay. $120 and good quality according to about 5-10 reviews here on OzHonda. Get a 2" mild steel mandrel bent backpipe with a resonator. Muffler of your choice. High-flow cat (ditch the stockie). Should be able to get the whole thing and installation for $600-800 max.

To answer the qs, yes it should, my n power headers are currently bolted to my stock cat, an also, wen I was epa, it was still fine, get n power, they r 100% fitment, an since they have the donut gasket flange, it will b fine, hope this helps ya, as for diy, its easy, I done it on the floor, jus unbolt the heat shield, undo o2 sensor, than manifold bolts, than the bracket bolts, lastly the cat bolts, but make sure u heat up the manifold before tryna do the o2, as its tight as mofo

Cheers for the replies guys. Eventually the whole exhaust system will be done, but i'm looking to upgrade in stages. I figured headers first to keep the popo away for awhile at least, then cat and catback which i got quoted around $350 from my local store. I'm not buying anything Toda or Mugen for a d series, you're paying for a brand when essentially all that is better is the steel/ceramic/etc piping and name slapped on it. Technically speaking all pipes flow the same and you're only looking at max a 10hp increase with a brand name part anyway.

http://www.ebay.com.au/itm/Honda-Civ...#ht_2458wt_905

That's what i'm currently looking at. I'll be installing them myself, cause honestly, it's piss easy if you've done a set before. Adult size mechano pretty much.

Good luck fitting it yourself because ebay headers are either shorter or longer, and i believe it would need modifications to fit.

Something as simple as replacing headers on B/D series is easy, but K20 u will struggle, simple cause of the location of where it sits, near the fire wall.... and its perfectly fine to do it in stages, Headers u will benefit the most, as thats where the power band is made, its all in the flow of the gases, oem is restrictive, with headers, u will notice a improved mid to top end power

A cat back will make the next modest gains, follow by a high flow cat...

I dont believe all pipes are the same, different materials make different sounds, density, weight etc etc, stainless steel will make the most raspy noisy but is the lightest, mild steel for strength, and than the most expensive, titanium, lightest and strongest off all the exhaust piping to date

and also how it was bent, crush bent, cheap, but does the job, mandrel bent, best flow, but more expensive to make, as well as the welding, how it was welded etc etc

alot to think about if ur tryna make the best for the car lol

Yeah, understandably. So much room in my engine bay it's not funny. Might just grab em and see how they go, only $160 shipped, and if they don't fit just sell them on i suppose. Description says they're mandrel bent, which is a bonus. Given how many d-series engines were made i'd assume most of the piping sizes and lengths for headers to cats etc would be the same across the range.

Thanks for the answers guys.

I installed 4-2-1 headers for 3 days before i had my full exhaust done to save $150 on installation. There mad on stock exhaust, it was so zippy when you just push the pedal a bit it was instant power. Then went to 2" exhaust + high flow cat and i lost some down low doesnt feel as zippy as the 3 days i had the headers on. But up top its way better. Just depends where u want the power i guess.

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Originally Posted by DC2-PWR

Good luck fitting it yourself because ebay headers are either shorter or longer, and i believe it would need modifications to fit.

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Unless u have personally brought N Power headers, than id say these beg to differ....... 100 percent fitment, with gaskets an all, no leaks, an the results = Great bang for buck, why spend 400 for Xforce when these do just as good for half the price :D

Do you think you'd be able to grab a link for the N*Power ones? I can't seem to find them.

Went ahead and forked out the $160 for the ebay headers. I'll let you's know how it goes, hopefully they'll be here by the end of the week! Can't wait, if they don't fit i'll just wait until next pay and head to the zorst shop and have them fit it, hopefully they don't try and milk me.

Hehe they'll fit mate. As for going to the shop, you should do it all at once if you have to do that. Doesn't matter if you can't afford it now, just wait until you can, it'll be cheaper to pay them for all in one go.

Haha, cheers for the support mate. Yeah, i'm gonna start saving for a high flow cat and 2" catback. Then onto some rims! If i get the chance i'll whack up a build thread i suppose.

hey man, late reply, but it may seem that they stop making headers for d-series :/

Yeah dude, i found their website but they didn't seem to have an d-series header listings so i ended up grabbing the ebay one. Cheers for the reply anyway dude!

Hey guys, sorry to bring up an old thread but just wanted a quick answer. Looking at getting a high flow cat next and wanted to know what size I should be getting? I currently have the N*headers installed but the rest of the exhaust system is stock. Which one of these would fit? http://www.nahux.com/NPOWER/category.php?category_id=40

Thanks!

Most likely a 2"/2.25"/2.5" cat will fit, I'd spend the money on getting a cat-back system done first though, or if you can bare the saving do the cat and cat-back all at once. Any good exhaust shop should be able to fit those sizes though.

I've payed more money than I should have by doing bit by bit lol.

Given that you have an EJ8 I'd consider either the 2" or the 2.25" and get a cat-back the same size to match it.

If I get the 2.25" cat, will it be a straight fit? Or will I need to take it to an exhaust shop to get welded in?

I doubt it would be a straight fit, as it will most likely be a bigger size than your exhaust size, however I may be wrong and the flanges may line up. I'd personally get it done at a shop anyway in case there are leaks or bolt issues and they will fit it regardless, shouldn't be too expensive either. I know I had a pain of a time trying to get my spring loaded cat bolts off.