non-US market OEM 4-2-1 exhaust
 

I am selling my UKDM 4-2-1 exhaust system.

It's generally held to be an improvement over the USDM 4-1 while maintaining the OEM look needed for smog:

It includes the 4-2, the 2-1, the heatshield, as well as the block-to-head gasket and gasket between the two parts.

If you want to replace the gasket between the two halves, it's Mazda part F20140306. It uses the same EGR tube as the US NB2.

I removed the studs from the header to clean the surface and could only find 2/3 :dunno: It's the same stud as the NB2 exhaust as well as a number of other Mazdas and I'll include the ones I found.

The front O2 sensor is in the crossover section and on a CA-spec NB1 it doesn't require an extension.

Asking $280 shipped.

https://lh3.googleusercontent.com/nT...00-h3600-rw-no

https://lh3.googleusercontent.com/dl...00-h3600-rw-no

https://lh3.googleusercontent.com/So...00-h3600-rw-no

https://lh3.googleusercontent.com/EF...00-h3600-rw-no

https://lh3.googleusercontent.com/I0...00-h3600-rw-no

https://lh3.googleusercontent.com/1V...00-h3600-rw-no

https://lh3.googleusercontent.com/Qq...00-h3600-rw-no

Very cool and interesting piece. Although I have to say you're entering used Racing Beat header at that price point.

Wow, Ive thrown heaps of these out (australia) Infact I probably have 2-3 sets in my scrap bin.

Dann

Some folks aren't able to swap headers when going in for smog, so unfortunately the RB is not an option. :(
People should feel free to make offers!

You've gotta start shipping these to the US, then! This set took a long friggin time to find - so many of the heatshields were totally rusted through. The 4-2 came from the UK to get the EGR bung and the heatshield+2-1 came from Japan. Shipping was ridiculous to get these parts here :vash:

This is only for NB, yes?

yup, NB only.

I figured. Anyone know if the JDM or EUDM NAs had something similar? I can't find a straight answer...

$280 shipped OBO!

sooo this would pass smog?

I smogged my car with this header on my car. However, you are deleting the first "light off" cat, henceforth referred to as :likecat:, (essential in startup emissions but not tested in your semi annual smog check). If you're second :likecat: is in marginal health, having both :likecat:s in the system might be the difference between passing and failing.

A couple notes on install. You're CA car has two o2 sensors. You're first sensor is between the exhaust ports and before the 1st :likecat: . The second is between the 1st and 2nd :likecat: . Since you are removing the first :likecat: you will need to add a bung behind the second :likecat: and install O2 #2 there and put O2 #1 in the new 4-2-1 header. The O2 sensors wires will likely need to be extended if I remember correctly.

Also, I'm not sure if the CARB EO for the CA miata states that it has two :likecat: but if it does and the smog technician actually checks it (not too likely) they can fail you for visual. But since it looks and is OEM you should be fine on that visual.


:hatecat:

ohhh i see thats a good way to get around it :) well i might just have to look into this but im not ready to put down the money yet :facepalm: let me sleep on it

This is one of the things I want once I'm ready to do exhaust. On the NB2 no one will know it's not stock.

Apologies for getting a little off topic, but it depends if your NB is a CA car or not. For example, my NB's emissions system is CA spec, and under the hood on the emissions sticker, it states that the car came with two cats. Depending on how ---- your smog tech is, you may be able to get away with this if they don't actually pay attention or care. If they actually do their job properly while inspecting a car with a missing cat, you'll get a tampered fail on your car's record (which your next smog technician may see if they pull up your record, which will likely cause them to inspect with more scrutiny). Remember, they actually have to fail a certain number of cars.

Assuming your car is running properly and your main cat is healthy, you shouldn't have a problem passing sniffer with no precat, though I can't say that I've tried.

I'd slap one of these on to my car if I was bringing it back to stock, though. I won't be doing that for a while though (fingers crossed). GLWS

I have two of these headers on my scrap bin from the two NBs I stripped, ready to be thrown away.
They are incredible heavy and I have a stainless steel 4-2-1 which I bought for 50€ ready to go on my NB once it is fixed.
Shipping them from Europe to US costs probably around 100$, so I am not sure they are worth their shipping cost?

Myself and a number of others have done this exact thing and passed sniffer and visual with no issue.
This particular NB1 model is ideal because on a CA-spec car the front O2 sensor is in the same place as the OEM setup. With the heatshield in place it looks exactly like they expect.

Incredibly heavy is relative - the CA spec NB1 exhaust manifold is ~40lbs IIRC.
Theyre definitely worth more than $100. Not that I'm saying you should undercut my for-sale listing, but based on the interest I've had in this 4-2-1 setup so far, if you listed yours up for a similar price I'm sure you could sell them for a profit. This setup is better than the OEM 4-1, and those already command prices of ~$150-200

This is about what I paid for mine once you factor out the shipping cost since it was a local transaction.

2 more scrapped yesterday..

If someone offers to buy them in bulk, Ill ship them.

Dann

While you've got one all off a car - how much does it weigh? (all up like in the first pic)

PMs replied.
I'll try to get the weight this weekend.

The parts come out to 20lb in total.
I also bought a replacement stud so you don't need to remove the ones from your existing manifold.

https://lh3.googleusercontent.com/Vn...00-h3600-rw-no

https://lh3.googleusercontent.com/yY...00-h3600-rw-no