BMW M3 Forum (E90 E92)

BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read


Go Back   M3Post - BMW M3 Forum > E90/E92 M3 Technical Topics > DIY Guides/ Discussions
 
Post Reply
 
Thread Tools Search this Thread
      04-15-2015, 02:51 PM   #1
DAT240
Registered
4
Rep
3
Posts

Drives: 2008 M3 E93
Join Date: Sep 2014
Location: Toronto

iTrader: (0)

M3 E93 pre-cat O2 replacement

My M3 has 125K km - engine light appeared, checked with the OBDII. The code read P2414 - bank 1, sensor 1 O2 sensor exhaust. I searched the forums, some info exists, but I'm posting this in case anyone else needs to change theirs.
First of all, I'm in Canada, so $ are in Cdn and measurements metric. I qualify for the seniors discount in most places, so no whining about working under a car with no room to move. Suck it up.
These are the pre-catalyst sensors. Bosch part number BOS1828336. $340 ea from the stealer, $233 ea online. Likely cheaper in the US, but that's the price I pay for living in the great white north. Bought 2 because I'm only crawiling under there once. The pre-cat sensors are labeled as "1" on the drawing. They are located in the exhaust, under the car, right before the catalytic converters.
You'll need a 7/8" wrench. Due to the cramped location I don't think that an O2 sensor socket will fit. The wrench worked perfectly.
I put the car on ramps, proceeded to move the cover around the transmission. Lots of small fasteners, not all the same type, so be anal and keep them separated.
The drivers side sensor is accessible. The connector comes apart by pressing the plastic bar down and pulling the connector. The sensors were not seized as i feared, likely due to the anti-seize compound. (The new sensors came with it already applied). Disconnect the plug first so that the nut will turn (duh). The connector is held by a U shaped clip. Slide the connector out of the clip, and there is also a clip for the wire. Reinstall the new sensor in reverse order.
The passenger side is the problem. There is a shield which prevents the connector from sliding out of the U clip. To do this "the right way" you probably have to remove the large aluminum plate under the engine bay, remove this shield, etc. I was able to loosen the bolt holding the shield in place (not too much or you'll be removing the big shield to find the bolt), then with a small pry bar I pushed the shield aside and was able to re & re the connector. No small children should be within earshot while you are doing this.
I reinstalled the transmission cover, zeroed the code with the OBDII. It has been a week of hard driving with no alarms. And I'm sure that the engine is running much better than before I changed the sensors. They definitely mess with the engine management functions. I can't comment on any improvement on the mileage (usually averages 12 L/100 km) because spring is here, the top is down and the engine just wants to go.
So, not a difficult fix, but a hoist and smaller hands would have helped. I worried that there were underlying problems, but my research indicates that the O2 sensors just wear out. In the meantime I'm happy to have my baby back.
Attached Images
   
Appreciate 0
      04-16-2015, 12:58 AM   #2
Gbyleveldt
New Member
2
Rep
16
Posts

Drives: E90 320d LCI, E92 M3
Join Date: Nov 2014
Location: Benoni

iTrader: (0)

Nice, thanks!
Appreciate 0
      06-15-2015, 09:48 AM   #3
MarkFT
Second Lieutenant
MarkFT's Avatar
128
Rep
258
Posts

Drives: BMW M3 (G80)
Join Date: Jul 2012
Location: Ontario

iTrader: (5)

Thanks for this...going to be attempting soon myself.
__________________
BMW M3 (G80)
Gone: 911 GTS, BMW 1M, E46 M3, X7 M50i, Porsche Cayenne GTS, X5M, M2CS, Cayman GT4 (981), Alfa Giulia QV, Carrera T, F80 M3 CS, Focus RS, M2 (OG), 14 E63S AMG wagon, M3 & M4 (F8X), X5 (F15 & E70), 335IS, VW Golf R (MK7), Audi SQ5, Cayman (987), M3 (E90), M5 MT (F10), A4 Avant (B8), S4 (B8), RS4 (B7), VW GTIs (MK2 to MK6)
Appreciate 0
      04-17-2016, 07:45 AM   #4
dpilat8588
Captain
66
Rep
614
Posts

Drives: E92 M3
Join Date: Oct 2012
Location: CLE

iTrader: (1)

Garage List
2010 BMW M3  [0.00]
Regarding the pre cat O2 sensors, do you use the same sensor for bank 1 and bank 2? Is this the correct sensor for both banks?

http://www.amazon.com/Bosch-17039-Ox...+Oxygen+Sensor
Appreciate 0
      04-18-2016, 06:17 PM   #5
VictorH
Major
430
Rep
1,286
Posts

Drives: '09 M3
Join Date: Dec 2007
Location: SC

iTrader: (4)

Yes, those are the sensors, same for both sides. Pretty good price.
Appreciate 0
      12-05-2019, 01:28 PM   #6
Scharbag
Colonel
Scharbag's Avatar
Canada
2618
Rep
2,134
Posts

Drives: 2011 E92 M3
Join Date: Oct 2017
Location: Victoria

iTrader: (0)

Garage List
2011 BMW E92 M3  [0.00]
Jesus - I get 12L/100km when cruising on the highway - down hill - with a tail wind - at 99KM/hr...

I average ~19L/100 around town. One of us is doing it wrong
__________________

2011 E92 M3 - 6MT, ZCP, ZF LSD, ESS G1, Some other goodies...
Appreciate 0
      12-20-2019, 11:41 AM   #7
eswaroop
Private First Class
22
Rep
119
Posts

Drives: '09 and '12 M3 Coupes
Join Date: Aug 2011
Location: Round Rock, Tx

iTrader: (0)

Did this recently on my car and it feels different - seems to run smoother but engine runs cooler and gas mileage a bit lower ( I think ) at 17 vs 18.5 mpg.. any ideas ? Does the car adaptation maps need to be reset or something ?
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 05:36 AM.




m3post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST