M3 E46 Pre Cat O2 sensor replacement...

mrgizmo04 · Mon, Mar-12-2018, 05:17:11 AM

I am not 100% sure what is going on in the last ~10 posts, but here are sensors I got (they are Bosch) on Amazon for a fraction of the cost.

Did not need to splice anything or change any connectors/plug.

Bosch 13949 Oxygen Sensor, OE Type Fitment (UPSTREAM - FOR CYLINDERS 1-3)
Bosch 13952 Oxygen Sensor, OE Type Fitment (UPSTREAM - FOR CYLINDERS 4-6)

Bosch 15138 Oxygen Sensor, OE Type Fitment (DOWNSTREAM - FOR CYLINDERS 1-3)
Bosch 13951 Oxygen Sensor, OE Type Fitment (DOWNSTREAM - FOR CYLINDERS 4-6)

Sent from my SM-G950U using Tapatalk

M3_Pilot · Mon, Mar-12-2018, 05:28:18 AM

Quote:

Originally Posted by mrgizmo04

I am not 100% sure what is going on in the last ~10 posts, but here are sensors I got (they are Bosch) on Amazon for a fraction of the cost.

Did not need to splice anything or change any connectors/plug.

Bosch 13949 Oxygen Sensor, OE Type Fitment (UPSTREAM - FOR CYLINDERS 1-3)
Bosch 13952 Oxygen Sensor, OE Type Fitment (UPSTREAM - FOR CYLINDERS 4-6)

Bosch 15138 Oxygen Sensor, OE Type Fitment (DOWNSTREAM - FOR CYLINDERS 1-3)
Bosch 13951 Oxygen Sensor, OE Type Fitment (DOWNSTREAM - FOR CYLINDERS 4-6)

Sent from my SM-G950U using Tapatalk

+1

Well. The parts. I bought mine from pepboys during an internet sale for a steal.

M3_Pilot · Mon, Mar-12-2018, 05:37:55 AM

Quote:

Originally Posted by TboneM3

BTB, why are you removing things? I just changed my pre cat o2s with a crow's foot and the only thing I did besides jacking the car up was removing the valve beauty cover to expose the harnesses for the O2s.

Yes, but don't you have euro headers? The sensors are placed further down the pipes as opposed to the us headers.

Quote:

Originally Posted by delvin

So just to clarify they are the same sensor with a different plug? I just got a SES for pre cat O2's tonight and I have no problem wire splicing.

Yeah, pretty sure that's the case. Funny, my SES light came on as well for my bank 1 pre cat so I ended up replacing it.

TboneM3 · Mon, Mar-12-2018, 05:50:46 AM

Ya you're right, I wasn't even thinking of stock headers.

As far as the sensors go, you cn but the OE/OEm part or you can buy a generic bosch and splice your old plug into the new sensor and save some $.

ctres · Mon, Mar-12-2018, 11:50:45 AM

Quote:

Originally Posted by TboneM3

Ya you're right, I wasn't even thinking of stock headers.

As far as the sensors go, you cn but the OE/OEm part or you can buy a generic bosch and splice your old plug into the new sensor and save some $.

Prices on these Bosch sensors are absolutely absurd, you are basically paying a massive tax get them with the BMW connector. Bosch is the OEM for tons of O2 sensors for other companies and can be had much cheaper, but you'd likely need to do some repinning. I probably wouldn't pay more than $30 for a narrowband switching O2 sensor personally. Luckily I haven't had to deal with this issue, but when the time comes you can bet I won't be buying a $100 sensor. You can get Bosch LSU 4.9 widebands for around $30 if you know what to look for, so there is no reason a narrowband with much older technology should cost $100.

delvin · Mon, Mar-12-2018, 01:56:40 PM

Thanks guys

Alex Sol · Tue, Mar-13-2018, 10:35:31 PM

@ctres i looked up the 4.9 wideband but couldn't find any for $30.. where would you find these?

ctres · Tue, Mar-13-2018, 10:50:41 PM

Motorcraft DY1303, DY1311, among others, but those ones I can confirm. I still need to check the pinout and connector against the typical aftermarket Bosch LSU4.9, but the sensors are legit Bosch.

Bosch and NTK are probably the two biggest suppliers of wideband UEGO sensors to the auto industry, and most new vehicles these days have factory widebands so they are getting very cheap. I'm sure there are other OEMs using the same Bosch sensors, but I haven't searched around much.

delvin · Mon, Apr-16-2018, 09:09:07 PM

Bought two of the 15703's for $25 each and installed this weekend after soldering the wires together. I've done 45 miles without any codes, mixed driving and a lot of idling. I got the code both times after idling in a line for 3-5 minutes.

If I was to do it again I would buy the 4 place weather pack connectors and hook them up that way instead of solder. I'd like to actually get someones defective O2's and redo it with the connector so in the future it would be plug and play without removing the beauty cover.

Mon, Mar-12-2018, 05:17:11 AM	#31
mrgizmo04 Registered User Join Date: Jan 2017 Posts: 1,250 In the garage: '05 BMW ///M3 Reputation: 0 Location: Menlo Park	Re: M3 E46 Pre Cat O2 sensor replacement... I am not 100% sure what is going on in the last ~10 posts, but here are sensors I got (they are Bosch) on Amazon for a fraction of the cost. Did not need to splice anything or change any connectors/plug. Bosch 13949 Oxygen Sensor, OE Type Fitment (UPSTREAM - FOR CYLINDERS 1-3) Bosch 13952 Oxygen Sensor, OE Type Fitment (UPSTREAM - FOR CYLINDERS 4-6) Bosch 15138 Oxygen Sensor, OE Type Fitment (DOWNSTREAM - FOR CYLINDERS 1-3) Bosch 13951 Oxygen Sensor, OE Type Fitment (DOWNSTREAM - FOR CYLINDERS 4-6) Sent from my SM-G950U using Tapatalk __________________ '85 528e 164k miles (sold) '05 M3 6MT coupe All DIY: 330 ZHP steering rack, diffsonline 4.1 diff with rem polish, E60 short shifter lever, AKG black diff bushings/subframe bushings, Rogue rtab, Rogue RSM with reinforcement, WPC rod bearings, Beyer driveshaft, full SS (SS stepped V1, catted S1, resonated S2, SS sport), Sachs clutch/flywheel, rear main, VANOS bullet proofing with anti-rattle, valve adjustment, cooling refresh. Last edited by mrgizmo04; Mon, Mar-12-2018 at 05:23:01 AM.

Mon, Mar-12-2018, 05:50:46 AM	#34
TboneM3 YNWA Join Date: Oct 2009 Posts: 6,643 In the garage: '04 BMW M3 E46 Reputation: 0 Location: Socal	Re: M3 E46 Pre Cat O2 sensor replacement... Ya you're right, I wasn't even thinking of stock headers. As far as the sensors go, you cn but the OE/OEm part or you can buy a generic bosch and splice your old plug into the new sensor and save some $. __________________ /// 2004 SilberGrau M3 · Coupe · 6MT · slicktop · manual seats · no nav______________________JOURNAL -Evolve-R Alpha N · Evolve CSL CF Airbox · Eventuri Scoop · AP Headers · Euro cat sect 1 · Dinan sect 3 · BMW Motorsport 4.10 · Besian · D/A pullies/fan delete · WPC rod bearings -TMS Camber & Subf plates · RE Street Trans Mounts · AKG poly SUB/DIFF · SDW RTAB · ZHP knob + UUC DSSR · GroundControl S/A (Koni/Eibach 440/550) + tall RSMs -OE CSL trunk · APEX 75mm Studs · Sportline 8S 18"x8.5/9.5" · MPSS 245/275 · ss brake/clutch lines -Pioneer DEH-80PRS · Eclipse PA5422 · CDT HD-6 + WS-100i · CDT EX-530 · 8" Kicker DD/Beater: 1999 Civic LX - Kenwood x998 · PPI 1600.4 · CDT HD-6 + HD-100 · CDT EX-530 · Clarion 10"

Mon, Mar-12-2018, 01:56:40 PM	#36
delvin Water Champion Join Date: Mar 2008 Posts: 573 Reputation: 0 Location: FT. Worth	Re: M3 E46 Pre Cat O2 sensor replacement... Thanks guys

Tue, Mar-13-2018, 10:35:31 PM	#37
Alex Sol Registered User Join Date: Jul 2014 Posts: 53 Reputation: 0	Re: M3 E46 Pre Cat O2 sensor replacement... @ctres i looked up the 4.9 wideband but couldn't find any for $30.. where would you find these? __________________ 1991 Guards Red Porsche 964 C2 2009 335d 2003 m3

Tue, Mar-13-2018, 10:50:41 PM	#38
ctres Registered User Join Date: Jun 2015 Age: 23 Posts: 359 Reputation: 0 Location: Detroit Metro	Re: M3 E46 Pre Cat O2 sensor replacement... Motorcraft DY1303, DY1311, among others, but those ones I can confirm. I still need to check the pinout and connector against the typical aftermarket Bosch LSU4.9, but the sensors are legit Bosch. Bosch and NTK are probably the two biggest suppliers of wideband UEGO sensors to the auto industry, and most new vehicles these days have factory widebands so they are getting very cheap. I'm sure there are other OEMs using the same Bosch sensors, but I haven't searched around much.

Mon, Apr-16-2018, 09:09:07 PM	#39
delvin Water Champion Join Date: Mar 2008 Posts: 573 Reputation: 0 Location: FT. Worth	Re: M3 E46 Pre Cat O2 sensor replacement... Bought two of the 15703's for $25 each and installed this weekend after soldering the wires together. I've done 45 miles without any codes, mixed driving and a lot of idling. I got the code both times after idling in a line for 3-5 minutes. If I was to do it again I would buy the 4 place weather pack connectors and hook them up that way instead of solder. I'd like to actually get someones defective O2's and redo it with the connector so in the future it would be plug and play without removing the beauty cover.

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