Euro headers

[gatorfast]

Saw a couple threads pop up recently on people installing euro headers on their US spec z4 m's and was looking for some clarification.

What exactly is involved in installing these? Seems like a sensor or 2 has to be relocated/fabricated...is this a difficult task for a shop to do? Will it throw any codes?

How could one expect the sound of the exhaust to change? Louder? More raspy?

Thanks for the help!

[iPhoneEngineer]

Heh I had this thread open in my browser since you posted, but haven't had a moment until now; hope the info is still useful. It took me hours of research to properly understand our exhaust system and what could be done with respect to the sensors without generating an SES light.

In short, if you remove the primary catalysts by installing Euro or other aftermarket headers, you will need a DME ("ECU") tune/reflash to suppress an SES light.

It is possible to run without an SES light, without the "secondary" O2 sensors, but not advisable. These secondary O2s are narrowbands which are still used to detect the failure of the widebands, even with the catalysts removed. This is important because oxygen sensors can begin to fail in a way that causes the engine to run too lean, risking engine damage if undetected.

My personal recommendation is to use headers that already have all 5 sensor bungs welded in--the 4 O2s and the EGT. Addition of secondary bungs to the section 2 has less reliable results.

I can recommend the Active Autowerke Gen IV headers, which I have on my car; good build quality, and absolutely perfect positioning of all sensors for ideal fit and clearance on the Z4M. Let me know if you have any other questions.

[johanness]

Originally Posted by gatorfast

Saw a couple threads pop up recently on people installing euro headers on their US spec z4 m's and was looking for some clarification.

What exactly is involved in installing these? Seems like a sensor or 2 has to be relocated/fabricated...is this a difficult task for a shop to do? Will it throw any codes?

How could one expect the sound of the exhaust to change? Louder? More raspy?

Thanks for the help!

Hey Gator. The step by step is really in every other thread on the Euro header subject.

1) Install header, relocate 02's and EGT to Section 1, unfold length from ECU
2) A good shop should be able to do this for you. A GOOD shop
3) I'm currently the only one throwing codes, but as of today maybe I've got it beat too. (see my other thread).
4) Louder, more raspy. Yes.

I think there's currently 4 threads dealing with this. It's not a hard job, but may be more poking around than some people are willing to do.

Originally Posted by iPhoneEngineer

My personal recommendation is to use headers that already have all 5 sensor bungs welded in--the 4 O2s and the EGT. Addition of secondary bungs to the section 2 has less reliable results.

Correct me if I'm wrong, but I don't think anyone here has attached all 4 O2's and EGT to their headers and gotten away without throwing any codes (and certainly not w/o a tune).
The whole point in moving the secondary O2's back is to mimic what's stock on our cars in Europe, and to not necessitate an aftermarket tune to 'turn down' the rear signals (although they're good for eking even more power out of them). It's simple and has worked for everyone (except me, until recently). The Primary O2's go in the header, and the rears in our Section 1 (along with the EGT). Lot's of photo's on the subject recently.

[Beedub]

iphone, pics of AA headers please??

[iPhoneEngineer]

Originally Posted by johanness

Correct me if I'm wrong, but I don't think anyone here has attached all 4 O2's and EGT to their headers and gotten away without throwing any codes (and certainly not w/o a tune).
The whole point in moving the secondary O2's back is to mimic what's stock on our cars in Europe, and to not necessitate an aftermarket tune to 'turn down' the rear signals (although they're good for eking even more power out of them). It's simple and has worked for everyone (except me, until recently). The Primary O2's go in the header, and the rears in our Section 1 (along with the EGT). Lot's of photo's on the subject recently.

I have all sensors installed in the AA headers, and have never seen an SES light. Yes, I have an ESS tune. I've used the headers successfully both with the ESS N/A tune, and the one for the VT2-500 kit. From what I have heard from ESS, they have managed to actually USE the signal from the secondary O2s as a check for the primaries, rather than just "turning them down" enough so they don't generate a catalyst fault. I don't have first-hand knowledge as to the truth of that, but have direct statements from them saying exactly that as the reason to significantly prefer including the secondary O2s in the system instead of just running the primaries.

As I mentioned in my post, my understanding is that a tune will always be required for a USDM car not to produce an SES light if the primary catalysts are removed...at least if you want to be sure. Yes, some have had luck by moving the sensors down, but many have suffered with chronic and intermittent problems doing so. The N/A tune is a significant step for our cars, especially with headers, so I think it makes sense to do the job right and get headers + tune as an SES-free package .

I'll make a thread on my AA headers install, with pics, when I get a chance (probably not until the weekend).

[johanness]

Originally Posted by iPhoneEngineer

my understanding is that a tune will always be required for a USDM car not to produce an SES light if the primary catalysts are removed...

That's the point I was making. No one on this forum that I know of is having a CEL by following the instructions above.
With a tune from AA, ESS or anyone else, you can attach the rear O2's anywhere u like; it doesn't make a difference. The point here is that you CAN mimic what's going on across the pond and run the car - no tune required.
Either way tho, headers are a great option for these cars

[gatorfast]

Hey Johanness, any sound clips yet of your remus setup?

[kennyfrc]

Can someone please post a picture showing where the wires are unfolded from the ECU to extend the harness?

Thanks!

[inTgr8r]

Originally Posted by johanness

......
3) I'm currently the only one throwing codes, but as of today maybe I've got it beat too. (see my other thread).
......................

I don't see an update

[inTgr8r]

Originally Posted by kennyfrc

Can someone please post a picture showing where the wires are unfolded from the ECU to extend the harness?

Thanks!

This thread has what you're looking for.

[kennyfrc]

Originally Posted by inTgr8r

This thread has what you're looking for.

Excellent!

Last question: Where do you get an EGT bung?

[iPhoneEngineer]

Originally Posted by kennyfrc

Excellent!

Last question: Where do you get an EGT bung?

Good question; also: what are the negatives of running without the EGT, assuming you have a tune?

[inTgr8r]

Originally Posted by kennyfrc

Excellent!

Last question: Where do you get an EGT bung?

Info is in here;
"EGT bung"

[johanness]

Originally Posted by inTgr8r

I don't see an update

Nothing to report yet. Too busy to get to the shop. Hopefully soon. I've still got my CEL. It's an EGT code (despite the fact it's installed where it 'should' be).

[Z4-VILLA]

I still get a plausibility code but no light.....then when shes warm everything goes away.... :-)

[inTgr8r]

Originally Posted by johanness

Nothing to report yet. Too busy to get to the shop. Hopefully soon. I've still got my CEL. It's an EGT code (despite the fact it's installed where it 'should' be).

lol... OK
Thought I was losing it there for a minute.

[marinb]

Has one tried anything like this, instead of doing a relocate:
http://www.frsport.com/Megan-Racing-...x_p_13668.html

Although I'm not sure if there is enough room for something like that.

[iPhoneEngineer]

Originally Posted by johanness

Nothing to report yet. Too busy to get to the shop. Hopefully soon. I've still got my CEL. It's an EGT code (despite the fact it's installed where it 'should' be).

It has never made sense to me that the EGT would be so far back on Euro setups-seems like it should be in the headers, like on USDM cars.

Some people seem to think there is no difference in software between Euro and USDM cars, and getting "just the right arrangement" of the sensors will allow a USDM's ECU to operate in the same way as a Euro one. Personally this seems implausible; does anyone have evidence that the USDM cars don't have different software, which is expecting different EGT readings than locating the EGT in the Euro position could provide?

Has anyone tried or had success with welding the EGT bung directly onto the euro headers instead of section 1?

[Beedub]

Originally Posted by iPhoneEngineer

It has never made sense to me that the EGT would be so far back on Euro setups-seems like it should be in the headers, like on USDM cars.

Some people seem to think there is no difference in software between Euro and USDM cars, and getting "just the right arrangement" of the sensors will allow a USDM's ECU to operate in the same way as a Euro one. Personally this seems implausible; does anyone have evidence that the USDM cars don't have different software, which is expecting different EGT readings than locating the EGT in the Euro position could provide?

Has anyone tried or had success with welding the EGT bung directly onto the euro headers instead of section 1?

i always thought the tuning for euro cars is different...

[inTgr8r]

^yes there definitely is.
According to ESS their header tune is based on the Euro tune.

[iPhoneEngineer]

OK, great, that sounds sane.

So why on earth are people trying to avoid a CEL with stock USDM software putting the EGT in Section 1 instead of in the headers? Obviously the temperatures it will be exposed to, most particularly on cold start, will vary and trigger a "plausibility" code.

For those running a Euro tune though, putting it in Section 1 is probably the right thing. I will confirm this with ESS when I talk to them about changing my headers to OEM in order to provide the best wideband read possible for the VT2-500's alpha-n setup.

[RobMCoupe]

Originally Posted by iPhoneEngineer

It has never made sense to me that the EGT would be so far back on Euro setups-seems like it should be in the headers, like on USDM cars.

Some people seem to think there is no difference in software between Euro and USDM cars, and getting "just the right arrangement" of the sensors will allow a USDM's ECU to operate in the same way as a Euro one. Personally this seems implausible; does anyone have evidence that the USDM cars don't have different software, which is expecting different EGT readings than locating the EGT in the Euro position could provide?

Has anyone tried or had success with welding the EGT bung directly onto the euro headers instead of section 1?

I have Euro headers and section 1 with stock US ECU. No fault at all since day one. I have driven over 3k miles.