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DIY: Ebay Headers

127K views 236 replies 51 participants last post by  robbyat 
#1 · (Edited)
Now I have picked up a lot of information in the last few months, i improperly installed ebay headers, reinstalled stocks, and am now going to install ebay headers correctly.:facepalm: If i had a thread like this it would have saved me a ton of time and money. while this site is a great source of information, it can be sometimes hard to find the correct information. So after all my research and purchases I have decided to make a new thread to go over the entire project inclusively. I am not making a DIY on how to do anything I am simply putting together some FAQ answers and a shopping list. Hope this helps out.


PS DO YOURSELVES A FAVOR AND READ THIS WHOLE THREAD, THERE IS USEFUL INFO ON THE SECOND PAGE.

First of all if you have no idea what any of this is please read this. It is known as Kpeng's thread. it contains a lot of good information even if it is a little outdated. so please read this first.

FAQ


1. Maks who should I buy from? Will it fit?

there are a few different ways to go about this. "surewinproducts" seems to be the dominent ebay seller right now and they sell quality products. generally they cost about $95 shipped to your door. however keep your eyes out for their auctions and you can get a set as cheap at $51 shipped.

the other option is to be part of a group buy. I think the F1 autohouse GB is closed but Anthony@BimmerBrakes is doing another one now. he is a good guy and will take care of you, but it will be more expensive. Here is the link. Good guy to deal with.

The cheap headers fit just fine but you can only put o2 sensors in the two lower bungs. but it will fit with no modification.


2. Ok I have bought the headers but I have no clue how to install them please help?!?!?!

this DIY is pretty good. scroll down a little to see pics. if you have specific questions please pm me, but like i said I AM NOT making a DIY on this.

3. I dont want a CEL light, I wanna pass inspection blah blah blah....

sure. we all do. Here is a DIY that will allow you to pass inspection. Just do what he did. A note on buying the o2 sim. o2sim.com has TERRIBLE customer service, plus the sim i got from them was not the appropriate one for my car, never managed to even talk to them. Buy the one from Anthony, he is a good guy, a strong forum rep, and an excellent vendor.


4. So you told me i would get a complete shopping list....

I did. here it is. the prices listed are approximate but it will help you get an idea. I listed parts numbers for a 323i. if you have a different car i suggest you visit RealOEM. when it comes to things like gaskets I always go OEM, you can use the ebay sh1t for cheaper but I do not recommend it.

HEADER INSTALL PARTS:
1 x Ebay headers $51
2 x exhaust manifold to header gasket + heatshield (11621732969) - $41.92 each
2 x header to exhaust gasket (18301436334) - $12.63 each
16 x header nuts (11721437202) - $.78 each
16 header studs (11127506203) - $.38 each
2 x bolts and nuts for connection between header and exhaust - (11621427586 - bolts: 18301737774 - nuts) $.99 each - (Can substitute Grade 8, M10-40 bolts)
1 tube of red locktite - $3


o2 SIMULATOR INSTALL PARTS (electronics and relocation stuff)
1 x o2 sim from Anthony at BimmerBrakes.com - $40
1 x small project box from radioshack - $3
1 x double sided tape
2 x 18mm 1.25 pitch nuts (muffler shop) - $5
1 x small socket box + cover - $5


Real life cost for everything is about $220.


Pictures of all the necessary stuff (or almost all of it) can be found here.

5. Maks, some people told my car will be super loud. is this true?

Loud is an opinion. For example for about 4 months i drove around with oem headers with reused ebay gaskets (cheap much?). Today when i went under the car there was basically a half cm gap between my headers and exhaust :facepalm:. so basically a dump. I didnt think it was that loud just kinda drony. I used new oem gaskets and tightened everything down, and my car is actually quieter than my buddies with stock headers and stock gaskets (never been touched) so whoever says headers are loud probably has an exhaust leak. So my car is OEM quite. Eurospec Muffler in the future i think :4ngie:

6. Tell the truth. Any negatives?
Not really. The only thing I noticed was a faint smell of gasoline when idleing for a longer period of time. No cats so this makes sense. not dangerous or harmfull.

7. OMGZZZZZ my engine is loping and throwing miss fire codes and crap and I dont know what to do.....!!!!!!!!

It will be ok. This is normal. All you did was mix up the precat o2 sensors. basically you put two o2 sensors into the headers. right? and you plugged them into the harness on the left side of the engine. right? Simply go and unplug both of them, and swap the connectors. Problem solved.


8. Maks do i need any special tools? any great tips?

-I would highly recommend a set of ratcheting wrenches and S wrenches. $20 at harbor freight for both, definitely worth it.

-take out the windshield wiper fluid tank, it will create space and make it easier to get to that nut on the very top first stud. when you get there you will know what I am talking about.

-DO NOT GRIND YOUR MOTOR MOUNT!!!!! comon guys its even called a motor mount - that means it supports your motor, you should NEVER grind down a thing that supports your motor. so if you cant get it to go back in it often helps to jack up the motor a little (you should already have a jack under it since one of the mounts is gone remember.....) It will fit. make sure you are putting it back in the right place.

- buy the stuff you need, dont cheap out. get good gaskets, an exhaust leak will make your car sound like a tractor dont ask me how i know.

- the precat o2 sensors HAVE to go back into the headers, its only the post cat ones that are relocated to the drugbin.

-The wiring harness for the o2 sensors takes almost as long to make as it takes to put the sensors in right (if you do it right) do it ahead of time so you just have to splice in the o2 connectors.
--get multi colored wires so you dont get confused when you extend the lines
-- at least 8 feet of shrink wrap in small sizes

-you can use the post cat o2 (stock) as the precat (simed) since they are longer, but if you do this pay attention to the connector. they are different and you will have to swap them.

--pull the secondary oxygen pump so you can get to the top bolts of the longer header from above.

Again if you have any questions please post here, or if its urgent feel free to pm me. but if you pm a dumb question that was answered in one of the links or in this thread i wont respond.


GOOD LUCK GUYS :thumbsup:


READ THIS BEFORE INSTALLING (it can save you hours)

OK. so after an unnecessarily long install, I have some advice in regards to this DIY (http://forum.e46fanatics.com/showthr...16#post7891216)...

1. Ratcheting wrenches are a MUST for the header nuts (smaller ones are better since you can get more of a turn per twist...combine a regular, longer wrench for tightening/breaking tension).
2. The passenger's side motor mount will require force and some prying (with a thick flathead) to remove and re-install (maybe its because we put my car on ramps instead of jack stands, since jacking the engine up simply pushed the car up, lol).
3. Before mounting each header, be sure to bolt on its respective pre-cat 02 sensor.
4. Re-assemble by bolting on the REAR header first. (that fvcking DIY took away 3 hours of me and my cousin's life by claiming the opposite).
5. Do NOT tighten anything unless you are completely positive that the next parts will have enough clearance for reassembly (with the exception being the rear header...just make sure the 02 sensors and plugs are installed before you do so!).

Lastly, get a towel to lay on because 85% of the procedure requires you to work from under the car. Mechanix gloves will also save you're knuckles and wrists from A LOT of punishment.

Take care fellas!

p.s. thanks again Maks, for making this thread!
-Keno
 
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#86 ·
Just an update...

When buying ratcheting combo wrenches to tighten your nuts on the headers, MOST of the metric sets out there dont have a 11mm wrench in them. 12 is too big. 10 is too small, naturally. However, 7/16 is very close to 11 mm.

I found this out 2 min ago when opening my new 7 piece metric ratcheting combo wrench set...

Guess whos going back to the hardware store...
 
#91 ·
Lol, I may end up just gleaning all the info from this thread as it comes up and never getting these damn things on the car! Every time I get on this thread some new trick or tip is posted!

Props guys! Making a challenging thing a little less challenging one post at a time! Now, can you pave my driveway, get me a day off, and make the summer temps go down? TIA!
 
#102 ·
Ordered mine 30 mins ago from surewinproducts and got em for $51shipped! I'm excited, to say the least. Now hopefully they'll fit on a 2003 325xi w/o trouble.

Oh and I need new cats. I was thinking of something from here. Possibly the Magnaflow #59905 or maybe the Magnaflow #59955.

My one problem left is figuring out where to put the cats and which of the two is recommended for performance (higher flow rate.)

If anyone can chime in and answer these questions it would be great!

Thanks!
deadwood
 
#103 ·
First check out summitracing.com - I am almost certain they beat that price by about 20 bucks. You need to be careful and make your sellection based on space, as it is limited. Also you have to place them as close to the engine as possible as cats have to heat up to work properly.
 
#113 ·
Installed mine this weekend, took 2 days because the fitment was so far off. Outlet on rear header was twisted a couple degrees, and the front header's outlet flange was 1/2" too short and angled wrong. Friend with a small mobile tig came and helped, but there's still a bit of strain on the headers and exhaust. I had to hack off the rear O2 bung from the rear header because it was hitting the body. Living with CEL for now, ordered sim from BimmerBrakes last week but Justin had to wait until this week before parts arrived to build one. I should have paid the extra coin for the headers from BimmerBrakes, but hindsight is always 20/20 and the headers I got were already near me in Canada.

Did my usual trick of wiping down the headers with WD-40 before starting the engine up for the first time. Stainless is a finicky woman, she remembers finger prints and grease marks forever. WD-40 removes all that, and when it evaporates off from the heat it leaves a nice honey coloured finish.

Idle is still dead quiet, part throttle is still quiet, and full throttle sounds angry (stock exhaust). Did a baseline dyno before I installed the headers, I'll be going back soon to check gains after I check the header nuts for tightness this week. Torque doesn't seem to drop off after 5000rpm anymore, it keeps pulling hard to 6500rpm. Torque drop at 6000rpm before was so bad it felt like a soft-touch rev limiter, not anymore!
 
#114 ·
MEOW!
Automotive tire Automotive exterior Bumper Auto part Tire


I meant to get a picture when it was on the lift but I tend to forget to do things I try to remember.

Do they fit the exhaust channel perfectly? Heck no! But they protrude less than the offset variety. They're staggered to try and keep the overall width down.

I didn't have the shop put the post-cat O2 bungs behind the cats because I would still get codes. The stock cats are insanely efficient (partly because they get so damn hot, and they're effing heavy) so when the computer compares the new cats to those, the new ones are found lacking.

phamine, where did you get your sim?

HTH

Man those welds are ugly.
 
#116 ·
MEOW!
View attachment 389460

I meant to get a picture when it was on the lift but I tend to forget to do things I try to remember.

Do they fit the exhaust channel perfectly? Heck no! But they protrude less than the offset variety. They're staggered to try and keep the overall width down.

I didn't have the shop put the post-cat O2 bungs behind the cats because I would still get codes. The stock cats are insanely efficient (partly because they get so damn hot, and they're effing heavy) so when the computer compares the new cats to those, the new ones are found lacking.

phamine, where did you get your sim?

HTH

Man those welds are ugly.
I got mine from Anthony. I may have to return them to him.

So what high flow cats are available that any cat efficiency codes.
 
#119 ·
I think 2.5" is a bit big. Measure the outer diameter of your exhaust piping (via calipers or string+math) to try and find the perfect size. If these cats are anything like Magnaflows (I think they're a clone) then no matter what size is listed, they will have a 4" diameter catayst. The sizes are merely for the fittings on both ends. A 2" cat in this case would have the same flow through the catalyst itself as a 3" model.

That said, the piping on my e46 had a 2" inner diameter so I got 2" cats.

As for the O2 sim, it's a dual-output unit so the one sim should cover both sensors.
 
#120 ·
Has anyone had issues with the 02 sensors hitting the engine? The guy installing mine called and said he cant mount them because the outlet for the sensors are right on the engine. Mine came with 4 02 sensor outlets and im almost 99% sure they're the right headers judging by the pictures from the other ebay header thread. Don't know what to do now..
 
#122 ·
Well either way if i can only use the lower 2 thats fine but he told me he can't even mount them because the pre 02 sensor outlets are hitting the engine. I have to swing by tomorrow to actually look at it but thats just what he told me right now. Didn't say anything about if he can put it on without using those outlets, just said he cant mount them.
 
#127 · (Edited)
WHat?! You CANNOT relocate the precats. They determine many things relating to combustion and feed the info back to the ECU and tell it to adjust accordingly. You can only put the post-cats in the drugbin and sim them. The pre-cat sims are there for a reason. If you remove them from the exhaust stream then there WILL be consequences.

Basically: put the pre-cat SENSORS in the post-cat BUNGS ON THE HEADERS and plug/block the pre-cat bungs on the headers. Put the post-cat SENSORS in the drugbin and then SIM THE POST-CAT SENSORS.

If you need proof, read the first post of this thread. Do not skim. Read his explanation of what happens when a pre-cat O2 sensor dies (same as relocation).
 
#129 ·
Ok so here's my question, the last time I checked, and I'm pretty sure it's this way, my post cat o2 sensors are wired and in mu dung bin...the pre cat o2's are in the headers...so I have o2 sims but havnt connected them yet but soon will however I have heard from different people that o2 sims won't really do anything....

Here is the full story: me and my friends put headers in the car...some how the pre cat ones ended up in the dung bin and post cat sensors were in the headers...car ran lean, bad mpg, loss of power....so switched the pre and post sensors around...car ran lean, bad mpg, loss of low end power....but then randomly my car started to run rich, bad mpg, loss of power....turns out my Maf was bad and crankshaft position sensor was bad....got It fixed....get car back and it's running lean again but car is stalling out at high speeds when in neutral....mech tells me it's Ccv so I replace it and VCG at the same time....now my question is: I heard from one member that headers will only cause catalytic inefficiency codes, no lean or rich codes, but Another fanatic told me it will run lean and catalytic inefficiency codes will appear....I'm putting my o2 sims in tomorrow, but will that resolve my running lean issue? ( btw i have yet to get a catalytic inefficiency code)
 
#130 ·
sounds like you got the o2 sensors backwards. this means that the o2 sensors that go to the headers should plug in on the left(if standing at front of car) side of the engine. the ones that plug in on top are post cats.

the other issue is that the precats have to be in the right order - your car is sensing the wrong order - so what you need to do assuming you have the right ones plugged in in the first place, is switch them. just unplug and replug should take all of 30 seconds on the sie of the motor. This is detailed in teh original post


7. OMGZZZZZ my engine is loping and throwing miss fire codes and crap and I dont know what to do.....!!!!!!!!

It will be ok. This is normal. All you did was mix up the precat o2 sensors. basically you put two o2 sensors into the headers. right? and you plugged them into the harness on the left side of the engine. right? Simply go and unplug both of them, and swap the connectors. Problem solved.
 
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