How to check which sideband sensor is for front vs rear bank?

iPhoneEngineer · 09-03-2011, 09:04 PM

EDIT: Sorry for the mistake in the title guys, it drives me absolutely nuts that Mac OS X auto-corrects "wideband" to "sideband" without asking--and the forum won't let me edit it.

I'm in the middle of the header swap now and am not sure I understand the marking I made to keep the sensors straight. I was much more careful the first time I did the swap...

How can I be certain which wideband sensor is for the front bank and which is for the rear? They lead to two connectors to the top left of the coils (viewing from the exhaust side)--is the top one the Front bank or the Rear bank?

I searched both the forum and the web and can't find anything but "don't mix up the ordering". Great.

Jumbosock · 09-07-2011, 12:51 PM

http://imageshack.us/f/263/s54o2sens...ectorsgw8.png/

Kinda late for you but this is the diagram I found. It has been a while since I did the swap so I can't 100% vouch for the diagram.

iPhoneEngineer · 09-07-2011, 01:00 PM

Fantastic, that's exactly what I was hoping for! I seriously couldn't find any such diagram, anywhere.

I intend to pull off the air pump and heat shield again to re-torque the header bolts now that they have heat cycled a few times, do a final check of the O2 wiring, and also fully torque down the sensors. I have another obligation tonight but this will happen by Thursday night.

If anyone else can confirm that the front header's wideband plugs into the furthest "up", "left" sensor harness on the valve cover, that would be great

.

Jumbosock · 09-07-2011, 02:52 PM

I think the original diagram was wrong. Here is another. Go by harness shape.

ZStig · 09-07-2011, 04:48 PM

crap, i wish I had time to find the info I used. search for e46 m3 header install threads. I used pelicanparts.com to confirm part numbers on the sensors to see which ones go where

I don't want to guess anything and tell you the wrong info.

iPhoneEngineer · 09-10-2011, 12:09 PM

So I checked out the harnesses and there is NO apparent difference between them; one can plug into the other. I also rechecked codes and don't have any new ones after a week of driving, so I assume that the sensor positions must be correct or the car would have complained by now... Still surprised it is this difficult to get information on the wiring.

Only slightly off topic--can anyone recommend a good service manual? Is there a P/N to order a BMW one from one of the online parts dealers?

09-03-2011, 09:04 PM	#1
iPhoneEngineer Lieutenant 43 Rep 476 Posts Drives: 2007 BMW Z4 M Coupe Join Date: Jun 2010 Location: La Honda, CA iTrader: (2)	How to check which sideband sensor is for front vs rear bank? EDIT: Sorry for the mistake in the title guys, it drives me absolutely nuts that Mac OS X auto-corrects "wideband" to "sideband" without asking--and the forum won't let me edit it. I'm in the middle of the header swap now and am not sure I understand the marking I made to keep the sensors straight. I was much more careful the first time I did the swap... How can I be certain which wideband sensor is for the front bank and which is for the rear? They lead to two connectors to the top left of the coils (viewing from the exhaust side)--is the top one the Front bank or the Rear bank? I searched both the forum and the web and can't find anything but "don't mix up the ordering". Great. Last edited by iPhoneEngineer; 09-03-2011 at 10:41 PM..
	Appreciate 0 Tweet Quote

09-07-2011, 12:51 PM	#2
Jumbosock Captain 76 Rep 987 Posts Drives: 2007 M coupe Join Date: Apr 2011 Location: San Diego iTrader: (0)	http://imageshack.us/f/263/s54o2sens...ectorsgw8.png/ Kinda late for you but this is the diagram I found. It has been a while since I did the swap so I can't 100% vouch for the diagram. Last edited by Jumbosock; 09-07-2011 at 05:07 PM..
	Appreciate 0 Quote

09-07-2011, 01:00 PM	#3
iPhoneEngineer Lieutenant 43 Rep 476 Posts Drives: 2007 BMW Z4 M Coupe Join Date: Jun 2010 Location: La Honda, CA iTrader: (2)	Fantastic, that's exactly what I was hoping for! I seriously couldn't find any such diagram, anywhere. I intend to pull off the air pump and heat shield again to re-torque the header bolts now that they have heat cycled a few times, do a final check of the O2 wiring, and also fully torque down the sensors. I have another obligation tonight but this will happen by Thursday night. If anyone else can confirm that the front header's wideband plugs into the furthest "up", "left" sensor harness on the valve cover, that would be great .
	Appreciate 0 Quote

09-07-2011, 02:52 PM	#4
Jumbosock Captain 76 Rep 987 Posts Drives: 2007 M coupe Join Date: Apr 2011 Location: San Diego iTrader: (0)	I think the original diagram was wrong. Here is another. Go by harness shape. Last edited by Jumbosock; 09-07-2011 at 05:07 PM..
	Appreciate 0 Quote

09-07-2011, 04:48 PM	#5
ZStig instagram 997turbotom 286 Rep 7,377 Posts Drives: Interlagos Z4MR Join Date: Jun 2008 Location: Delray Beach, FL iTrader: (4)	crap, i wish I had time to find the info I used. search for e46 m3 header install threads. I used pelicanparts.com to confirm part numbers on the sensors to see which ones go where I don't want to guess anything and tell you the wrong info. __________________
	Appreciate 0 Quote

09-10-2011, 12:09 PM	#6
iPhoneEngineer Lieutenant 43 Rep 476 Posts Drives: 2007 BMW Z4 M Coupe Join Date: Jun 2010 Location: La Honda, CA iTrader: (2)	So I checked out the harnesses and there is NO apparent difference between them; one can plug into the other. I also rechecked codes and don't have any new ones after a week of driving, so I assume that the sensor positions must be correct or the car would have complained by now... Still surprised it is this difficult to get information on the wiring. Only slightly off topic--can anyone recommend a good service manual? Is there a P/N to order a BMW one from one of the online parts dealers?
	Appreciate 0 Quote