Euro headers and euro cat FINALLY installed!

[bmwschnell]

I finally got around to doing the header install. I ordered the headers from Donovan, and they were in excellent condition. There was a delay in receiving them due to the freak snow storm in England, but they eventually arrived.



I jacked my car up and took off the old headers. It's such a good feeling to have those restrictive US spec headers off.





I originally decided to fabricate my own cat using the stock part. Thanks to Beta and Finnegan for the o2 and EGT bungs, I had my buddy weld them on there for me. They won't win any beauty contests, but I pressure tested them after MIG welding and NO LEAKS. I threw a little brass on top of the EGT bung too to make sure there would be so leaks.




After welding the pipe up, I decided to give it one more shot to try and find a used euro spec cat. I've been trying for a while to find a used one because brand new, they are like $2000. So I hit google.de, and low and behold, I found a Z4M euro spec cat from a car dismantler in Germany. The part had fewer than 5000k on it and the price was only 650 euros so jumped on it. I speak German so this came in quite handy with the whole process. The dismantler shipped the part with Deutsche Post Luftpost. After almost 3 weeks, I had about given up on receiving it, but then the post office called and said they had a package too big to deliver. As usual, the Germans were very meticulous, and the part had PLENTY of protection for the journey. I could barely fit it in my other car. It took me 10 minutes just to unwrap it.



Here is my euro spec cat!



And here is the euro cat compared to the one I made. I am planning on keeping the cat I made as a backup, but if the euro cat continues to function, I will probably sell the one I made on here.



I "unfolded" my o2 wires. Luckily length wasn't an issue since my part from Germany came with the euro spec o2 sensors. However, I did have to switch the EGT sensor because the euro spec cable didn't mate with the USA spec. I was very careful to make sure the sensors were plugged in correctly. Hopefully the sensors that came with the euro cat will function, but if not, I still have the original post o2 sensor cables from my car that I can install. All that was left to do was to take it for a test drive.

I took my car out and did a drive cycle. It took about 20 or 25 minutes, but I did not get any CELs! In total, I have driven about 35-40 miles since the install. Fingers crossed that a CEL doesn't pop up. I couldn't quit smiling because the acceleration just felt brutal. However, it did seem to lag a little bit it in 2nd gear. I'm hoping this is because the DME has not had time to adjust completely. Either way, I have ordered ESS euro spec software, so I'm thinking this will take care of it.

I hope it all works out!

[itdnwiwbp]

Looks great! Thanks for all the pics. Can't wait to get around to this myself.

[bmwschnell]

Thanks! I would like to update that I've driven about 75 miles now with no CEL, and the lag in 2nd has stopped. I think the DME has adjusted. The added power just makes up the car feel right. So far so good!

[johanness]

Looks like it was done right. You won't get a CEL with your modded piece. Congrats either way.

However after looking at the added length of the Euro Sec1 next to your mod'd US one... I'd keep yours. Less cat / more power. Sell the Euro.

[Swashplate]

I just put my CSL headers on from Donovan. Sounds fantastic.

Did run into a snag with my Euro Cats though. As they came out of an M3 I am going to have to have the flanges rotated 90 degrees. Kinda odd they did that but whatever.

[Finnegan]

Great write up. Nice work on your modified section too. No leaks and works > beauty!

Talk about packaging! That's an amazing amount of protection!

[bmwschnell]

Thanks guys! I'm just hoping the sensors that came with the cat are functioning properly because I reaaaally don't want to get back under the car to take them out. Taking off the x-pipe is a pain, and I found that there isn't enough room to get to the secondary o2s while the s pipe is still in place. That means I'll have to unhook it from the headers too. Oh well.

Johannes, I'll have to think about which cat to use. Although the one I made would work fine and probably give more power, I like knowing that my car is pretty much European stock. I get my ESS euro tune tomorrow so we'll see how that goes.

Swashplate, I couldn't find the csl headers, but the regular euro M3 headers really make the car sound more aggressive. I can only imagine how the csl headers would sound.

Finnegan, I was concerned about it possibly getting stolen in the German Post system. I read a german article about rising theft. It was seemingly taking forever (although after looking back on it, delivery only took 1 more day than their 12 business day estimate), so I started looking up things on the internet. That's never a good idea because you then hear all the horror stories. But after getting the cat, I'd like to have seen somebody try to steal it by casually walking out of the sorting facility with that huge box hahaha

[Swashplate]

Originally Posted by bmwschnell

Thanks guys! I'm just hoping the sensors that came with the cat are functioning properly because I reaaaally don't want to get back under the car to take them out. Taking off the x-pipe is a pain, and I found that there isn't enough room to get to the secondary o2s while the s pipe is still in place. That means I'll have to unhook it from the headers too. Oh well.

Johannes, I'll have to think about which cat to use. Although the one I made would work fine and probably give more power, I like knowing that my car is pretty much European stock. I get my ESS euro tune tomorrow so we'll see how that goes.

Swashplate, I couldn't find the csl headers, but the regular euro M3 headers really make the car sound more aggressive. I can only imagine how the csl headers would sound.

Finnegan, I was concerned about it possibly getting stolen in the German Post system. I read a german article about rising theft. It was seemingly taking forever (although after looking back on it, delivery only took 1 more day than their 12 business day estimate), so I started looking up things on the internet. That's never a good idea because you then hear all the horror stories. But after getting the cat, I'd like to have seen somebody try to steal it by casually walking out of the sorting facility with that huge box hahaha

Oh I am sure they sound very very similar. Oh that glorious sound and the popping, gurgling sound on overun....mmmmmmmm

[bmwschnell]

Well it looks like I may have jinxed myself. I drove about 165 miles, and no CEL came on. I decided to go ahead and install my ESS software. After I had installed it, I checked my codes, and I had these 4 codes:

2c9e Control heater sensor after cat
2c9f Control heater sensor after cat (bank2)
2c92 EGT sensor electric
2c93 EGT sensor plausibility

I've cleared them and will see if they come back on. If they do, I have a suspicion that it may be the o2 sensors that came in the euro pipe.

Hmmmm

[seank]

If the mid-section is FS, please contact me. Thanks

[bmwschnell]

Originally Posted by bmwschnell

Well it looks like I may have jinxed myself. I drove about 165 miles, and no CEL came on. I decided to go ahead and install my ESS software. After I had installed it, I checked my codes, and I had these 4 codes:

2c9e Control heater sensor after cat
2c9f Control heater sensor after cat (bank2)
2c92 EGT sensor electric
2c93 EGT sensor plausibility

I've cleared them and will see if they come back on. If they do, I have a suspicion that it may be the o2 sensors that came in the euro pipe.

Hmmmm

Well it turns out that the problems have resolved. The only time I had the codes were immediately after I installed my ESS tune. Apparently I didn't read the directions very well, because the ESS directions said that this usually triggers codes and to clear them off. If they come back, let them know. I called ESS and spoke to Roman. He said as long as they didn't come back on, there was nothing to worry about. I'm happy to say that I've driven about 400 miles since and no CEL and no codes. The car pulls like a train and sounds incredible. The wheels break loose when shifting into 2nd gear. That never happened when the car was stock.

[Jumbosock]

Nice!

[pal]

Congrats! And now put this car on a Dynojet and post up an SAE plot. I am curious if the Euro cats flow better that US ones.

[johanness]

Originally Posted by pal

Congrats! And now put this car on a Dynojet and post up an SAE plot. I am curious if the Euro cats flow better that US ones.

My bet is they don't. Look at the size of them compared to the US Sec 1.

OP, please get her on a dyno as Pal suggested.

[elwesso]

Very nice summary of the mod... I think maybe next year (or over the winter) this will be something I'll do, seems like the bang for the buck is unbeatable.

Do you have the stock exhaust otherwise? What's the difference in sound like with the stock exhaust?

[bmwschnell]

Originally Posted by elwesso

Very nice summary of the mod... I think maybe next year (or over the winter) this will be something I'll do, seems like the bang for the buck is unbeatable.

Do you have the stock exhaust otherwise? What's the difference in sound like with the stock exhaust?

I would definitely recommend this mod to anyone with a Z4M. It is well worth the price. I bought my M new in May 2007 so I didn't want to do any work on it to void the warranty. Back then, there just wasn't much in the aftermarket to choose from. Around 2011, people started doing this header swap, and I told myself I'd do it once the warranty expired. I just didn't actually get around to doing it until a few months ago.

I don't have a completely stock exhaust. My mufflers are Eisenmann Sport. Some jackass rear-ended me last summer so I got his insurance to buy me new mufflers. However, even with the new mufflers, the sound difference between the stock headers and the euro headers is just all-around better. It's a little deeper at low rpms, but starts to scream at higher ones. The other big differences that I've noticed are at idle and when you let off the gas. It sounds more exotic now at idle because it kind of has that blop blop blop blop sound. When you let off the gas, there is a good, but not obnoxious, amount of back-cackle. I feel like I have a new car.

[z3speed4me]

Is there a "go-to" source for acquiring the euro-headers?
I would think the power differences between these and say supersprint are minimal to none, and I'd love to stay OEM.

Just starting to put my ducks in a line for "if" I grab a coupe/roady soon...

[bmwschnell]

Originally Posted by z3speed4me

Is there a "go-to" source for acquiring the euro-headers?
I would think the power differences between these and say supersprint are minimal to none, and I'd love to stay OEM.

Just starting to put my ducks in a line for "if" I grab a coupe/roady soon...

Yes, member Donovan will hook you up. Also, the euro cat that I made is for sale

[Blind32]

Originally Posted by z3speed4me

Just starting to put my ducks in a line for "if" I grab a coupe/roady soon...

"If" !?!? don't be silly

DO IT!

[z3speed4me]

The only IF, is me deciding on MZ4 or another MZ3 but S54 this time. The headers would fit either...