Euro headers, what's needed?

[UntzUntzUntz]

Got a set of euro headers I will be installing pretty soon so I want to make sure I have everything prepped up before I start taking everything apart.

What's exactly needed to pull off a euro header swap?
So far I've gathered the following:
- 18 manifold studs Part #: 07129900298
- 18 manifold nuts Part #: 11721437202
- 6 Header gaskets Part #: 11627830667
- 4 Header to exhaust bolts Part #: 11621318568
- 4 Header to exhaust nuts Part #: 18301317898
- 2 Header to exhaust gaskets Part #: 11627830668
- Air valve control gasket Part #: 11727505259
- 8 Front axle reinforcement plate hexagon screw Part #: 31106772199

Which items am I missing and which are unnecessary?
I've read that pretty much everything besides for the header to exhaust connections are one time use. Is this true?

Also, sorta off topic, the euro headers I ordered look like complete trash compared to my OEM ones as far as cleanliness goes, any way to clean them before installing them? lol

Thanks!

[Steeler]

Can't speak to the parts needed or not but if you want the headers to look nice have them glass beaded or go the extra step and have them ceramic coated.

[UntzUntzUntz]

Originally Posted by dbarton62

Can't speak to the parts needed or not but if you want the headers to look nice have them glass beaded or go the extra step and have them ceramic coated.

LOVE to ceramic coat it, but I live in California. Police here love to open people's hoods and make sure theirs nothing life threatening like euro headers, so unfortunately I can't let it grab too much attention.

Glass beading didn't cross my mind however... Thank you my good sir

[Jumbosock]

You don't need the 18 studs. Maybe 2 or 3 in case u pull one out and have issues with it. Even if u pull one out (they can stick to the nut) you can reuse them but it's nice to have spares. The 18 nuts are supposed to be one time use so it's a good idea to get new ones. Don't throw all the old nuts away. You might need one in the future.

The header to exhaust nuts and bolts can be reused (so no need for new ones) but I did have two of mine rusted so I did buy new ones. I actually don't like the OEM ones because they use funky star fittings.

The 8 reinforcement plate bolts are also supposed to be a one time use item and so you are correct in getting 8 new ones but I would just reuse my old ones. Supposedly they stretch a tad for proper torque fitting but I think that's a bit excessive. If u don't mind the price. Get them. Again, don't throw away some of the old ones in case u need one later in life.

The air valve control gasket is a little thing. I would reuse mine but if u wanna be safe get a new one.

Everything else on your list I would say is a must to get new.

If it's been a long time since you've gotten post cat O2 sensors, this is a good time to replace them. They go out so easily it would be a good idea to replace them now.

Also when the header is out is a perfect time to replace the ring seal on your constant pressure valve. It's a 5 dollar item and way easier to replace without the headers in the way. Plus they tend to go bad. Don't get a new CPV. Just replace the seal.

[StickMon]

^WHS
Definitely do the CPV O-ring, if you haven't already.

[UntzUntzUntz]

The more research I did about the o-ring the more surprised I got of how unaware I was about this issue. Thanks guys this saved me a lot of time and headaches down the road.

Oh and I looked more into how to clean the headers... My coworker recommend I port the headers, recommended a good place but seems a bit excessive don't you think?
My other option is to get a couple flex-hone's, do it myself and pocket the money for a tune afterwards?

And last question, I promise, will the sensors reach the secondary cats if I were to relocate them?

[pokeybritches]

Where will the EGT sensor go?

[RossBMWZseries]

I've been keeping up with this thread myself as I'll be getting euro headers soon along with DKF section 1. These are extra costs I was not aware of This might be my last Valentine's with my gf when she finds out what I'm doing. I was thinking of buying her headers for Valentine's. When she doesn't know what they're for, she might just give them back to me

[Jumbosock]

Originally Posted by UntzUntzUntz

And last question, I promise, will the sensors reach the secondary cats if I were to relocate them?

Yes they will reach but it takes some work. Watch my videos here.
http://www.zpost.com/forums/showthread.php?t=800574

You will need to weld in an EGT bung and the O2 sensor bungs. In my video I have euro cats which already have the bungs.

[UntzUntzUntz]

Originally Posted by Jumbosock

Yes they will reach but it takes some work. Watch my videos here.
http://www.zpost.com/forums/showthread.php?t=800574

You will need to weld in an EGT bung and the O2 sensor bungs. In my video I have euro cats which already have the bungs.

You're lucky with the euro cats. Not only are they hard to find but cost an arm and a leg. Great work on the videos it's very informative

Originally Posted by pokeybritches

Where will the EGT sensor go?

And since Jumbosock is using euro cats, figured I'd see how OEM euro is setup... and there she is...



I'm ordering the header parts, o-ring, and a couple flex-hones tonight. Can't wait for the low end torque it needs and THE SOUND. I'll try to keep this thread alive with the progress.

Thanks guys you're helpful as always!

[Reborn_]

Question for you guys. I'm buying an 07 Z4MC next week from out of state. Car has euro headers and aftermarket exhaust. To smog the car here in California, I am going to have to at least swap the exhaust back to stock for the visual check. Stock parts are included. The question is, are the euro and usdm headers direct replacement for one another? Will the stock exhaust bolt up to either header? I'm trying to decide if I need to replace the entire exhaust system, or just the catback.

Thanks all.

[badhbtz]

Billswebspace.com has a good write up on the components needed. Just click on the Z4M he owned

[Jumbosock]

Originally Posted by Reborn_

Question for you guys. I'm buying an 07 Z4MC next week from out of state. Car has euro headers and aftermarket exhaust. To smog the car here in California, I am going to have to at least swap the exhaust back to stock for the visual check. Stock parts are included. The question is, are the euro and usdm headers direct replacement for one another? Will the stock exhaust bolt up to either header? I'm trying to decide if I need to replace the entire exhaust system, or just the catback.

Thanks all.

Everything is interchangeable. The question is the sensors.
What is currently in place of Section 1?

[Reborn_]

Originally Posted by Jumbosock

Everything is interchangeable. The question is the sensors.
What is currently in place of Section 1?

So I'd like to apologize in advance. I don't have the car yet, so I am not very familiar with the setup.

This is the mod list:

Euro Z4M spec headers
Custom DKF exhaust section one with interchangeable resonators, 100 cell and 300 cell cats
Supersprint Powerloop mufflers

I think (please verify) that Section 1 refers to the dual pipes that have an "S" curve to them and has cats or resonators?
So it would go Engine -> Header -> Section 1 -> Center Silencer -> Mufflers

I think the center silencer is probably stock since it's not mentioned; if I'm lucky, I can simply swap the supersprint mufflers with stock?

[itdnwiwbp]

You've got the configuration correct. However, with Euro headers and a DKF section 1 experience on here indicates that passing CA smog will be a challenge if not impossible. Several, myself included, bought the DKF section 1 because Euro section 1s are so rare hoping (because we were told they would be) that they would be adequate. I've since acquired a Euro section 1 and will be selling my DKF to someone outside of CA who can get some use out of it. Your Powerloops won't be an issue unless the tech doing your visual is a stickler. They won't effect emissions. Hope you're able to get things working.

[Reborn_]

Originally Posted by itdnwiwbp

You've got the configuration correct. However, with Euro headers and a DKF section 1 experience on here indicates that passing CA smog will be a challenge if not impossible. Several, myself included, bought the DKF section 1 because Euro section 1s are so rare hoping (because we were told they would be) that they would be adequate. I've since acquired a Euro section 1 and will be selling my DKF to someone outside of CA who can get some use out of it. Your Powerloops won't be an issue unless the tech doing your visual is a stickler. They won't effect emissions. Hope you're able to get things working.

Thanks for the info. I was actually only worried about visual, but if I am going to be at risk for the sniffer too, then it would require stock Section 1. That is probably more work than I'm willing to do. I may just go to my "guy."

But in case I decide to do the work, then I can leave the euro header in place, and swap the stock Section 1 and mufflers on, correct?

Also, as a general question, are those cats or resonators on the header itself? Is there a cat in the center silencer?

[itdnwiwbp]

If you leave the Euro headers in place and reinstall the stock NA section 1 there will be nowhere for the EGT or post-cat O2 sensors to go. Probably easiest to go to your "guy".

In the NA headers are CATs that, as I understand, only work during the first few minutes after start up until the CAT in the section 1 gets up to temperature. There is no cat in x-pipe.

Also, currently I'm running NA headers and the DKF with just the resonator in place. I believe someone on here recently said that setup just barely passed CA smog but recommended ensuring that the CATs were good and hot before performing the test.

[Reborn_]

Ok, thanks again for the info. So basically I'm looking at a complete exhaust setup swap if I want to do it legit.

[itdnwiwbp]

Legit, yes. I don't wanna say there's no other way to pass but if the Euro headers are what's currently installed it does complicate things. If you've got a "guy" though you should be ok, right?

[StickMon]

I would suggest putting the headers back to stock, including the O2 and EGT sensors.
That should get you past the sniffer test and mitigate potential check engine light issues.
The rest you can season to taste.

I have stock headers, RE section 1, which is just pipes with no cats or resonators, stock X-pipe, and RE cans.
The sound is incredible, passes the sniff test, and E-Z Smog has no idea what a stock Z4 ///M is supposed to be, and really don't care.
Depending on where you are in SoCal, you may want to try them. On La Palma in Chino, near the Stoney Lonesome.

[pokeybritches]

I thought California got rid of the sniff test?

I have OEM U.S. headers and S-pipe I could let go if you're interested.

Your description of the stock exhaust is correct - the S-pipe and section 1 are the same piece. The stock U.S. exhaust has four parts:

1. Catted headers (this is where the primary and secondary O2 sensors are. The car you're looking at has catless Euro headers, so the secondary O2 sensors (the ones that used to check catalyst efficiency) have to be move into the S-pipe to avoid a check engine light. The car's computer must sense a cat between the primary and secondary sensors.

2. Catted section 1, or S-pipe. The DKF system replaced this component with a much better, free-flowing system. The OEM U.S. section 1 does not have O2 sensors. The Euro and DKF do. DKF is the least restrictive of the two.

3. Resonated section 2, or X-pipe. This is a crossover to help with exhaust scavenging and improve sound. It sounds like this system is stock on the car you're looking to purchase.

4. Mufflers, or section 3. The main reasons people swap these out are for sound tuning and looks.

If you went back to the OEM U.S. setup, you would lose 20+ horsepower and a lot of sound. As long as the car isn't throwing a check engine light, you can pass emissions (assuming no sniffer) if your guy gives you the thumbs up on the visual.

The DKF cats haven't been proven to pass or fail emissions. There's not a lot of data out there... yet. I have a theory that it's all related to cat temperature. The people passing have ceramic coatings or forced induction. The ones failing do not. At the same time, my friend with non-coated headers has put his 300 cell cats in and had no CEL, so the jury is still out.

[RossBMWZseries]

Originally Posted by pokeybritches

I thought California got rid of the sniff test?

I have OEM U.S. headers and S-pipe I could let go if you're interested.

Your description of the stock exhaust is correct - the S-pipe and section 1 are the same piece. The stock U.S. exhaust has four parts:

1. Catted headers (this is where the primary and secondary O2 sensors are. The car you're looking at has catless Euro headers, so the secondary O2 sensors (the ones that used to check catalyst efficiency) have to be move into the S-pipe to avoid a check engine light. The car's computer must sense a cat between the primary and secondary sensors.

2. Catted section 1, or S-pipe. The DKF system replaced this component with a much better, free-flowing system. The OEM U.S. section 1 does not have O2 sensors. The Euro and DKF do. DKF is the least restrictive of the two.

3. Resonated section 2, or X-pipe. This is a crossover to help with exhaust scavenging and improve sound. It sounds like this system is stock on the car you're looking to purchase.

4. Mufflers, or section 3. The main reasons people swap these out are for sound tuning and looks.

If you went back to the OEM U.S. setup, you would lose 20+ horsepower and a lot of sound. As long as the car isn't throwing a check engine light, you can pass emissions (assuming no sniffer) if your guy gives you the thumbs up on the visual.

The DKF cats haven't been proven to pass or fail emissions. There's not a lot of data out there... yet. I have a theory that it's all related to cat temperature. The people passing have ceramic coatings or forced induction. The ones failing do not. At the same time, my friend with non-coated headers has put his 300 cell cats in and had no CEL, so the jury is still out.

Corrected