Reason for JDM Header not fitting !

[AJ PwR Jr.]

I have receive PMs from a few memebers here asky me "why the JDM header will not fit" Here's the reason.


Left : stock header (size 28mm) vs Right :JDM aftermarket header (32mm)


The stock USDM header has a O2 bung to fit in the O2 sensor !


Where is the O2 bung on the JDM after market header

The header will bolt up just fine but if you seriously want to fit any brand JDM header then you will need to drill a hole and weld on the O2 bung. You have to make sure the O2 sensor aligns properly because if the sensor stick too far in or out, it will affect the reading to the stock ECU.

Thanks
Ben

[aira]

Great info.

I won't be moddin my motor though as I'm wanting to do a k-swap when available.

[Jonniedee]

AT least the stocker is a tube header and not a cast manifold...

[JDMJunkie]

Originally Posted by Jonniedee

AT least the stocker is a tube header and not a cast manifold...

Yea, the OEM ex. mani doesn't look too bad.

[dougiepants]

Seems to me that Honda of America is F'ing us... Well I guess it is custom fab time maybe down the road...

[JDMGD3]

Honestly this doesnt suprise me at all. I have already experienced this with my other car where the JDM exhaust manifolds dont have the O2 located in the primary manifold like the US version but instead its in the secondary manifold or otherwise known as the downpipe. I can almost guarantee that this is the case with the JDM Fit as well that the O2 bung's stock location is in the secondary and not the primary like with the US version.

But for some reason the JDM aftermarket manifolds for the Fit come only as a primary with no downpipe so like Ben said if your wanting to use a JDM manifold, basically the only option is to make a O2 bung on the manifold in the stock location of the stock manifold.

[Popeye]

Any dyno plots with the aftermarket header?

Also is it a J's or Spoon?

[dougiepants]

J's has one in the AJ-Racing Vendors forum...

[sLiVeRwOrM]

man.. i would not pay $500+ on something i have to modify anymore..

[crxgator]

im sure you can make an extension harness for this to work...ive done it before on my crx when i used a y8 header on it...

[AJ PwR Jr.]

We are making the T1R header now and I will get that dynoed as soon as I get the prototypes. The T1R header will bolt just right up with no modifications.

[xbowner]

You have to remember when buying jdm parts like this, that although it may be a similar motor in the Jazz, there are differences within motor layout and o2 censor/header/exhaust positioning and routes. I have a feeling even if you did drill the hole, it still wouldn't line up 100% in terms of the lines, plus you'd more than likely throw a cel reguardless even if you did manage to make it fit.

Not trying to make anyone up set here, its just in real life, jdm performance parts are rarely ever able to line up perfectly without any kind of further modifications.

[sLiVeRwOrM]

Originally Posted by AJ PwR Jr.

We are making the T1R header now and I will get that dynoed as soon as I get the prototypes. The T1R header will bolt just right up with no modifications.

now that sounds like something id be intrested in..

[dougiepants]

Will it be able to bolt up to all USDM and JDM exhausts?

[aziatiklover]

nice but I think any muffler shop can drillit for us?? wat do u think??

[bitterspeak]

Originally Posted by aziatiklover

nice but I think any muffler shop can drillit for us?? wat do u think??

I doubt it. Too much work. It's not as simple as drilling a hole. From what I see, the USDM headers are longer. So first you would have to cut the lower flange off and weld an extention that has a O2 bung. And then weld the lower flange back on.

In my opinion, it's not worth it.

[dougiepants]

I am going to wait to see what T1R header puts down compared to the JDM Headers...