///M Lambda / o2 sensor

[AndyBeech]

So after a recent thread by another member regarding o2 sensors, I thought I'd look into mine and I think I could benefit from a new set of pre-cat sensors (post cat seem much less prone to fouling / failing). Now these are quite an integral part of the fueling/ignition system so it stands to reason that people are reporting improved running with a new set fitted, around 60k+ seems like a good time for a check / replacement.
I've got my car booked in at Redish for an Inspection 1 in November at which point I'll get them to fit a new set. In the meantime, I've got plenty of time to source a couple of these bad boys (should be replaced in pairs IMO). Call me tight, but no way am I paying £200 each for a Lambda sensor from BMW when it's made by Bosch and BMW literally just sell it on at a massive mark-up, that's an M tax too far in my opinion (although a few other BM's use this sensor as well).

Now, I've picked up one of these sensors from BMW today so I can compare with one from elsewhere let's say. I'll be returning it tomorrow for a refund as I literally just want to have a look at it to satisfy my own curiosity/confusion on the 6 pin/6 wires situation.

This is the BMW one for our cars: (BMW Part number 11787540167) (Bosch part number: 0258017092)

As you can see 6 pins and a pink switch - Open / Closed

Definitely only 5 wires here(white,grey,yellow,red,black)......so why 6 pins? Spoke to a Lambda reseller this morning, he says it's a Bosch thing, one pin is to test and calibrate it, it's not used when it's on the car.....so says. Does kind of make sense.

The BMW and Bosch part numbers stamped

Rip off!

Anyway, so that's the one you'll get from BMW. Having had an hour to scour the net for results with the Bosch part number, there's plenty of places that sell them, mostly for around the £100 mark. So without the hideous BMW stamped part number, your saving approx. £200, not too shabby really.
Now it's just a case of weeding out the reputable companies from the not so.

ECP can't get the part in despite listing it, rubbish.

An outfit called Green Spark Company (or something similar) get their parts direct from Bosch Germany. Excellent! Listed for £110 each, bargain. Phoned them up and asked when they can get them in stock, said they would phone Bosch in Germany and find out for me and call me back......phoned back 5 minutes later, bad news. Apparently, due to the VW scandal going on at the moment Bosch are not currently selling any of these parts as they are being 'investigated'. I guess not specifically this part, but a lot of their sensors as no doubt all these Germany Car Manufacturers use Bosch parts. Bugger! A few other companies I emailed also said they couldn't get the part in and didn't know when they would be able to.......so it does add up I guess.

So now it's companies that hold stock of these only. I should add, BMW no doubt have a stock pile of these sensors, the one I got from them was stamped '2014' so no doubt just sat in main warehouse somewhere until needed. So I doubt getting one from them will be a problem.

I've yet to settle on a company to buy these from at the moment, but there's lots of German websites around the 100 euro mark each so I'll probably give one of those a shot and I'll post up comparison pics when they are delivered and performance results once fitted.

Pretty boring I know, but if this saves someone £200 getting ripped off by BMW then all the better I say. I usually buy all my parts from BMW but I think they're really taking the mick with the price for these hence the thread, otherwise I wouldn't bother!

If anyone wants to look, try typing the Bosch part number into Google typing it as 0 258 017 092 gives different results to typing it all in a line

[mr wilks]

Does seem as the miles grow & years add these could become a "to do" job
Good work

[TomK]

Nice one Andy, I was going to look into these as the bmw price is a piss take. Even an e46m3 one is considerably cheaper (won't fit but pretty much identical). Let us know where you end up ordering from.
Cheers

[AndyBeech]

Nice one Andy, I was going to look into these as the bmw price is a piss take. Even an e46m3 one is considerably cheaper (won't fit but pretty much identical). Let us know where you end up ordering from.
Cheers

Yup, it's almost a scam to be honest, I wouldn't mind if BMW had some input into it in terms of manufacturing, or making it specific to the Z4M, but it's not, just a generic Bosch part that BMW stick in their own box and flog on for nearly 100% more than it should be. Buggered if I'm paying towards their swanky new dealership in Reading, even if it is quite an impressive dealership now!

The E46 M3 one is a slightly different design, has 4 wires / 4 pins and is a shorter length / differing lengths, looks a different design as well for whatever reason. Being the same engine I can only imagine it's a DME driven difference that it takes a new design of Lambda but yeah a lot cheaper, around £70!

Anyway, getting it in stock is definitely an issue at the moment. A lot of German/Euro Bosch sellers are saying the same as companies here, it's not in stock and don't know when it will be

[GuidoK]

I always thought the z4m came with the lsu 4.2 widebands, but your's is saying 4,9
(4.2 takes reference from outside air, 4,9 takes reference from internal air chamber afaik)

Anyway that connector is pretty standard for lsu 4.2 and 4.9 sensors. You can get generic ones as low as £60 or so.

The 4 pin O2 sensors are narrowband.

[AndyBeech]

I always thought the z4m came with the lsu 4.2 widebands, but your's is saying 4,9
(4.2 takes reference from outside air, 4,9 takes reference from internal air chamber afaik)

Anyway that connector is pretty standard for lsu 4.2 and 4.9 sensors. You can get generic ones as low as £60 or so.

The 4 pin O2 sensors are narrowband.

Ah cool, good info, yes getting a bit of an education looking into these! Mostly the same part's with different wire lengths is the biggest difference more than the sensor itself.
It's definitely LSU 4.9, I've been told by a few companies now that the specific Bosch part for the Z4M is out of stock but other Bosch sensors which are the same but have a slightly longer wire are available. Notably part no: 0258017025 is in essence the same albeit a slighty longer wire......decisions decisions! I'll probably keep scouring for the Z4M one and if I can't find one just go for one of the other sensors with a slightly longer cable.
The more I see of basically the same Lambda but with different wire lengths sub £100, the more I find BMW's asking price a total piss take!

[TomK]

Hey Andy, I've found someone who has the correct bosch Z4M ones in stock in the UK, http://www.lambdapower.co.uk/
Unfortunately he only has 3 in stock and I have just ordered 2 which should be with me tomorrow, but you could at least replace your older one of the two by ordering the last one. I tried ordering from germany last night but the order was cancelled this morning as they could not supply.

[Z222M]

I got a full set of four sensors from lambdapower.co.uk for just under £350 in total earlier in the year. They are made by Bosch. Two were in stock and two came from Germany.

Had no problems at all.

[srhutch]

I got a full set of four sensors from lambdapower.co.uk for just under £350 in total earlier in the year. They are made by Bosch. Two were in stock and two came from Germany.

Had no problems at all.

Obviously before the VW saga kicked off, which seems to be affecting things.

[AndyBeech]

Hey Andy, I've found someone who has the correct bosch Z4M ones in stock in the UK, http://www.lambdapower.co.uk/
Unfortunately he only has 3 in stock and I have just ordered 2 which should be with me tomorrow, but you could at least replace your older one of the two by ordering the last one. I tried ordering from germany last night but the order was cancelled this morning as they could not supply.

Cheers Tom, I spoke to these guys yesterday and was about to pull the trigger on an order from them, but snooze you lose! All good though, spoke to them today and they're getting some more in next week, week after at the latest which is no problem, don't need them till November.
Glad you got a couple mate, good saving there and seem like decent guys as well so hopefully can recommend these guys to others in the future all being well

[TomK]

I feel bad now! To be honest I'm going to put them in and see if they cure a slight start up niggleI have. If they don't make any difference to that and I don't notice any difference in the behaviour in general then you're welcome to have them off me.
Will know by Monday arvo.

[AndyBeech]

I feel bad now! To be honest I'm going to put them in and see if they cure a slight start up niggleI have. If they don't make any difference to that and I don't notice any difference in the behaviour in general then you're welcome to have them off me.
Will know by Monday arvo.

Not at all mate, it's all good, I started the thread to help others out so no problem at all. I've actually ordered the parts now through them for delivery in the next few weeks which is plenty of time for me
Hope it fixes your problem, let us know how it goes, will be interested to hear.

[TomK]

Oh good, hope it helps yours too.
The issue I'm hoping to sort is a lumpiness on a cold start process whereby as the revs come down from the initial 1200 or so to the normal 850 or whatever it is the engine will run very lumpy for 20s or so. In all other circumstances the engine starts and idles absolutely fine. The thinking is that one of the sensors heating circuit is not operating to spec, though it's a guess as there are no fault codes present, which is a bit odd as there would be if the heating circuit was not functioning. We shall see..

[Babw]

Oh good, hope it helps yours too.
The issue I'm hoping to sort is a lumpiness on a cold start process whereby as the revs come down from the initial 1200 or so to the normal 850 or whatever it is the engine will run very lumpy for 20s or so. In all other circumstances the engine starts and idles absolutely fine. The thinking is that one of the sensors heating circuit is not operating to spec, though it's a guess as there are no fault codes present, which is a bit odd as there would be if the heating circuit was not functioning. We shall see..

Thanks for the link you posted Tom, I've just ordered a couple as well for the same issue you're describing.

I'm going to be booking an inspection 2 in the next few weeks so hopefully a new MAF, pre cat O2, new fuel filter, sparks, coils and filters will make a difference. If not I'll be quite pissed off!

[TomK]

Interesting you have the same issue, I couldn't find much info out there on it. I'll let you know Tuesday if it's resolved.
You know the fuel filter is inside the petrol tank on these cars right? Right pain in the ass to change.