MVRK - The Updated "Everything You Need to Know About Ebay Headers" Thread

Nothing was in backwards. I am definitely running better now but not totally there. I am yet to be able to plug up the post cat 02 sensor bung in header bank 1 and I believe this is leading me to missfire in cylinders 1, 2 and 3. Does this make sense? Since there is much less backpressure in that header than the other I should be running rough, right?

There is absolutely no room to plug up that damn hole cause it is too close to the underbody of the car. I hope I can figure it out tonight and finally get my AA software tomorrow.

Originally Posted by mvrk10256

glad it worked out.



cause you want the extra power.



everything is fixable.

I am doing it more for the sound than the power. I guess when I get really to tackle this I may get the bungs moved to I have room for the post O2 sensors that people keep going on about.

What's the biggest issue with the bungs? Too tall allowing no room? How should I position them?

Originally Posted by drumbum624

Nothing was in backwards. I am definitely running better now but not totally there. I am yet to be able to plug up the post cat 02 sensor bung in header bank 1 and I believe this is leading me to missfire in cylinders 1, 2 and 3. Does this make sense? Since there is much less backpressure in that header than the other I should be running rough, right?

There is absolutely no room to plug up that damn hole cause it is too close to the underbody of the car. I hope I can figure it out tonight and finally get my AA software tomorrow.

Ya you absulutly have to make it fit. without an o2 sensor the computers AFR maps are all ****ed.

Originally Posted by zander271

I am doing it more for the sound than the power. I guess when I get really to tackle this I may get the bungs moved to I have room for the post O2 sensors that people keep going on about.

What's the biggest issue with the bungs? Too tall allowing no room? How should I position them?

if you get headers from Anthony@bimmerbrakes you dont need to worry about anything. if you get them off ebay it can be a crap shoot. I got mine to fit, just make sure you screw them into the headers before bolting the headers up to the car...

[QUOTE=mvrk10256;13158851]Ya you absulutly have to make it fit. without an o2 sensor the computers AFR maps are all ****ed.
QUOTE]

Without a post cat 02 sensor? what if I have them rerouted to my drugbin. Obviously without pre cats I would have problems but the way it is my only problem should be the open hole right? Would that hole be the cause of my codes and poor performance?

sorry the precats have to be pluged in, and into the right header too. buy you want to put the plugs into the open holes if I were you.

Okay everything is plugged and all vaccum leaks are sealed and the car is hooked up the way it was before I did the install...minus the cats. My engine is running a lot better but it still feels liek I am missing. It is accelerating slow and I am definitely getting some misfires but I cannot tell where exactly. Currently I am throwing missfire codes in all 6 cylinders but that is because I have been swapping my coils aroudn to determine if it is a coil and which coil. Any suggestions?

Originally Posted by drumbum624

Okay everything is plugged and all vaccum leaks are sealed and the car is hooked up the way it was before I did the install...minus the cats. My engine is running a lot better but it still feels liek I am missing. It is accelerating slow and I am definitely getting some misfires but I cannot tell where exactly. Currently I am throwing missfire codes in all 6 cylinders but that is because I have been swapping my coils aroudn to determine if it is a coil and which coil. Any suggestions?

take a deep breath and trust me. go on the side of your engine right above your new headers unplug both sensors and plugthem into the other ports. your problems will magically go away...

i had work all day yesterday and am about to go again today so i havent really gotten to my car. tomorrow I will try this for sure. they are just kinda a PITA to get to and to screw them in but if this does it for me I will be super happy

They should be really easy to get to. They are just on teh side of the engine in clips, just yank them and swap them. takes all of 30 seconds.

alright maks I could not get to those clips because there wasnt enough room really. the wire going out of the clips to the sensors was too short and didnt reach up high enough for me to get a good grip and unclip them. But I noted the color of the wires coming out of that clip and they were brown, black, yellow, and red/white. I also took a look at the two clips sitting smack dab in the middle of my engine on top and they had corresponding wire colors coming out of them. Do these lead to my 02 sensors as well? I tried swapping them out and I got the same codes. Maks I trust you and I know you know alot more about this than I do, but I read what you said about making sure the correct 02 sensors ended up in the corrects place and I really did label them and make sure that was the case. I think I am leaning towards it being my coils.

Originally Posted by drumbum624

alright maks I could not get to those clips because there wasnt enough room really. the wire going out of the clips to the sensors was too short and didnt reach up high enough for me to get a good grip and unclip them. But I noted the color of the wires coming out of that clip and they were brown, black, yellow, and red/white. I also took a look at the two clips sitting smack dab in the middle of my engine on top and they had corresponding wire colors coming out of them. Do these lead to my 02 sensors as well? I tried swapping them out and I got the same codes. Maks I trust you and I know you know alot more about this than I do, but I read what you said about making sure the correct 02 sensors ended up in the corrects place and I really did label them and make sure that was the case. I think I am leaning towards it being my coils.

It can be your coils, but the chance of all your coils going bad at the same time right after a header job is pretty small. so let me try to lay this out for you (its hard cause i am not there to just point with my finger)

the engine harness that goes to the top fo the engine is for the "post cat" sensors - those are the ones we dont care about - you can sim them, you can just trash them, it doesnt matter to the opperation of the car. the ones on left side of the engine (with you staring at it from the front of the car) go tto the precat sensors - those are the one that control your AFR and stuff like that. what happens is people lable them to make the plugs match - but no one ever notices which physical header they go into to. (I made this same mistake) so while your markings match up they may not be in the same headers as when we first started. Make sense?

the other issue is that the style of plug for the precat and the post cat sensors is different. On my car we swapped the plugs - because of the crappiness of the ebay headers I had to use the lower (post cat) bungs for my precat sensors - this made the wires too short to plug in correctly. You can either manually extend all 4 wires, or you can simply use you old "post cat" sensors and swap plugs. this will give you enough length of wire to plug them in correctly.

I really hope you unerstand what I am trying to say, believe me if I could somehow show you it would make a lot more sense. But I went through this exact same thing, I even tried to warn people in the beginning of this thread.

good luck and dont hesitate to pm me to get a faster response.

i got your warning at the beginning of this thread dont worry. that is why i made sure to label them header bank 1 pre cat and header bank 2 pre cat.

I thought the post cat sensors had two white wires in them as well (something to do with heating maybe). I was just surprised that the colors of the wires between the harness on top of the engine and going to the pre cat sensors are the same, that makes me think they have to be the same thing.

About the coils, I have a perfectly good reason for them to go bad. and that reason is because I am an idiot. I missed an engine ground when I was putting everything back together and then ran the car afterwards. It ran for a bit, but then it would start back up the next day until I realized I needed to reconnect it. I don't think I fried my DME cause it will run fine for a little bit at first but after a few miles start missing. I will update you guys when I get new coils in.

I also plan on trying spark plugs later today, but I don't think those are my issue.

the white wires are heating wires - to take accurate measurements there is a heating element in every 02 sensor - both the precats and post cats have heaters. so 1 o2 sensor has 4 wires total 2 for heating and 2 for measurement.

I would still try to swap them because what you are talking about is exactly the same thing that happened to me when i had them plugged backwards. I just dont want to see you drop big money on coils when you doing need them.

Well I have to say that you were completely right and I was completely wrong Maks. I apologize for being so stubborn with you. As I'm sure you know these cars can be quite frustrating. It took a bit of manuevering but I finally got those plugs to a spot where I had a good reach and could actually unclip them. I had left the labels on the 02 sensor wires from when I started the install and I was astonished when I looked at the label on header bank 1 and it said "Pre-cat Header Bank 2." I thought I was so careful about that but apparently not careful enough. I switched the connectors and my car runs like a champ. I can't wait to see what the AA tune does to it.

Thank you Maks for all your help and thank you e46fanatics!

Originally Posted by drumbum624

Well I have to say that you were completely right and I was completely wrong Maks. I apologize for being so stubborn with you. As I'm sure you know these cars can be quite frustrating. It took a bit of manuevering but I finally got those plugs to a spot where I had a good reach and could actually unclip them. I had left the labels on the 02 sensor wires from when I started the install and I was astonished when I looked at the label on header bank 1 and it said "Pre-cat Header Bank 2." I thought I was so careful about that but apparently not careful enough. I switched the connectors and my car runs like a champ. I can't wait to see what the AA tune does to it.

Thank you Maks for all your help and thank you e46fanatics!

glad to hear you are running right again. I understand the feeling. when i did this for the first time, I made the same mistake, until some kind soul pmed me at about 3am local time, to tell me what he had learned, it was long before this thread came about, and told me the trick. I went out to my parking lot, flipped it and went for a drive.

enjoy your new found power

just wanted to chime in, I did headers on my 330 last weekend (as well as rotors, pads, SS lines, was a lot of work in one weekend).

The DIY is pretty much bang on. About half of my studs backed out. Those nuts are the easy part though believe it or not, you can reach all but 2 or 3 of the nuts from the top with just a 3in extension. Rest are easy from the bottom and some creative extensions (wobble socket helps some, just be careful). You WILL have to remove the motor mount and jack the engine up to get the front manifold out, we tried to avoid this and after 2 hours of banging/prying the hell out of everything we decided we had to do it.

The rear manifold comes out first, you can wiggle it it out before you jack the engine up. Putting new ones in, rear header has to go in first. Loosen exhaust hangers and scoot the exhaust back a little. I broke 3 bolts out of 4 on the old exhaust flange, they just snapped in half.

I completely removed the SAP, with a block off plate from ECS. So glad its gone I hated that noise. I also removed my rear O2 sensors completely, since they are pointless.

You don't have to remove the engine covers unless you plan on unplugging the rear O2 sensors. Oh and yes, make sure you label your O2 sensors, I just put a dab of silver paint on the front O2 connector and that was it. Post cat O2s aren't even worth putting back in, save em for spares.



This was really really hard, but not complex or anything. Just exhausting (lol).

Oh, performance wise... BADASS. You definitely pull harder at the top end. Don't really notice it before 3500 rpms though. But yeah, sounds GREAT with the stock exhaust with golf tee mod. At idle it is silent like stock, but get on it and it has a nice tone, that gets all raspy and M3 like when you are ripping on it. And you will get that nice backfire sound when engine braking, much much louder than stock. Also, the gas smell when parked. I am used to it from a convertible with straight pipes

Mine has a leak at the exhaust flange because the gaskets I got were bad, but it still sounds awesome. I'm gonna get some OEM gaskets, I know the flanges are fine and those suckers are torqued down tight.

So eevrywhere I've read says that oem gaskets are $40 but pelican parts has them for 20. Just fyi

And flange gaskets are 10

Sent from my DROID2 GLOBAL using Bimmer App

I plan on ordering ebay headers tonight and was wondering which of the 3 main sellers were most reliable to send the right headers for a 328i/323i ebstores, tuning pros, or motorsportpartz?

replied to ur pm

Is it possible to install all 16 studs then slide the headers on or do the headers have to be lined up then studs put in? I already have my studs/nuts/gaskets but my headers havent arrived yet. Also has anyone cut the heat sheild off of the header gasket for easier installation of the headers? Im wondering if i'll have problems with melting wires if I do.