Lambda Lambda o2 lambda........
 

Ok I am confused, thought I knew what was what till searching on here and finding lots of different answers........

I have just bought a STi v7 UK bugeye. It has got a CEL light permanently on and that reads as code p0031, which I understand to be the front o2 sensor in the headers, just before the up pipe. Ok so far......

Now I am definately trying to avoid Subaru prices, so in an effort to find out what lambda cross reference part number it is, I have looked on here and searched for others and found 2 views...

So the official part number is, 22641AA042

My questions are, is this a 4 wire Zirconia standard lambda or is it a true wideband like an innovate jobbie which uses Bosch 0258007057 Wide band.

If it is simulated wideband then will a universal 4 wire zirconia do?

Or does it have to be the genuine part? (I would be surprised if so).


Is it 4 wire or 3 wire.

Seems to be a common prob so someone must know...

Please clear my confusion.

You could try japperformanceparts, I did on exactly same code. £75.

Yep nice one I shall,

Just wondered if you knew what type it is, just for interest as I ve been looking at lambdas all day now and would like to know :D

Pretty sure it will be 4 wire, 3 wire is old hat nowadays, as to wideband or 2 point, I've no idea, but you will need to replace it with the same!

Simon

Cheers Simon,

Yeah was just wondering really as some on here say use 4 wire zirc one which is roughly £30 and some say you have to use the oe one which is £292 + vat.

Just trying to clear it up really.........

I was under the impression that the Newage ECU expects to find an OEM pseudo-wideband lambda and does not recognise alternatives :(

Shaun

It will be a 4 wire, The front & rear lambdas are the same beast apart from the notches on the plug & the length of the wire.
the rear is only used as a Cat sensor, You could swap the plugs over & use that in the headers & put a cheaper universal in there if you wanted.
I did have one which i bought for my Sti7 before i sold it & then the lambda !!

Dean

Exactly correct the one in the headers is a wide band and only available as an o/e part. There around about the £250 mark +vat


A replacement 4 wire sensor will not work in the headers

My mate had the exact same problem on his 2002Sti about 2-3 weeks back. Its a 4 wire jobbie which plugs into a grey connector under a plastic cover near the drivers side suspension turret, you probably already know that bit. You have the correct part number and main stealer wanted £291ish + VAT. He couldn't find one secondhand, tried API, Grade A and all the usual places. I found it on SubaruParts.com in the US for just over $201 I seem to remember including shipping. His car has done 72K and it was a right barsteward to get out. New one fitted from main dealer and fault cured.

Good luck!

Andy.

SubaruParts.com link to part

Ah I see thanks for all your advice.

So a standard 4 wire wont do and it has to be the right one.

In my efforts yesterday managed to find it cross referenced against a saab part on a 9-2x 2.0lt Turbo Aero, part number 32005978, but unfortunately saab dont have any of those either, so no luck there!

Just for those that are interested, it was a walker products sensor from the US part number 25054004, but cannot find these in this country either.....:mad:

I have managed to buy a secondhand one from Bucks Subaru and should receive it Wed all being well.

Still not entirely convinced that there isnt a cross referenced part.........

Cheers all

Jonny

Well seen as we are on about it here is the diffinative article from Walker Products inc in America, and even mentions the correct a/f sensor for our vehicles, but on a Honda.....

From walker products:-

Air Fuel Ratio Sensors are identical in appearance to any 4-wire standard
Zirconia Oxygen Sensor. The Air Fuel Ratio sensor has a wider range of operating
parameters than the standard zirconia sensor. Thus, it is important to
clarify that there is a significant difference in sensor types and their operation. In
the case of Air Fuel Ratio Sensors, incorrect replacement of this sensor with a
normal oxygen sensor can lead to malfunction, illumination of the check engine
light, and the possible setting of an engine code. (MIL)
For example: The selection of a standard 4-wire Oxygen Sensor 250-24620
could be installed instead of the correct Air Fuel Ratio Sensor 250-54005 for a
Honda application. These two sensors are nearly identical in appearance,
therefore all criteria must be followed to ensure the correct part number is installed.
To insure the selection of the correct part number:
1. Verify the correct engine size and engine number. There may only be the
difference in the final 2-3 digits of the engine number.
2. If you are unsure of the engine number, you must verify the OE number of
the sensor currently on the vehicle. The OE number is normally printed
on the sensor housing.
3. Once the OE number is identified refer to the OE Interchange in the
Walker Catalog to select the proper sensor part number.

Right here goes....... probably gonna get a slating for this but I tried.

After 2 days of researching, I have come up with a small reference chart for A/F ratio sensors of the same type fitted to other vehicles and part numbers.

I can not guarantee any of the info as its all just theory (cos I have bought a 2nd hand one!), but if I was in the same situation again, I would go from this chart and save a few quid. (I have found the NTK one, at lambdasensor.co.uk for £64)

Anyways its up to yourselves, if though you take the plunge and give it a go, do me and everyone a favour by posting your results!

The doc is a pdf and I can't post it here, so if you would like one then click on:-

http://www.craven-college.ac.uk/jonn...ce%20chart.pdf

Hope this helps everyone else........