Hi all - as per subject, does anyone know the correct part numbers for the oxygen sensors on the CAYC engine, or where to find them out from?

Firstly I think there's only one lambda/oxygen sensor. Are you used to petrol engines?

 

Here's a webpage showing the two different options for LHD (L0L) and RHD (L0R), as the last two item 1 part numbers.

Car Parts Catalog - LLLParts

 

What makes you thing it has a problem?

 

Breezy_Pete, a question from an innocent bystander. Why are they different for LHD and RHD? Is it just cable lengths?

Edited 4 December, 20241 yr by Jocko

@Jocko, yes I expect that's the difference. 

22 hours ago, Breezy_Pete said:

Firstly I think there's only one lambda/oxygen sensor. Are you used to petrol engines?

 

Here's a webpage showing the two different options for LHD (L0L) and RHD (L0R), as the last two item 1 part numbers.

Car Parts Catalog - LLLParts

 

What makes you thing it has a problem?

 

I may well be using the wrong word! I admit to being thoroughly confused between differential pressure sensors, lambda sensors and oxygen sensors… and am not knowledgeable about cars or engines in general at all!

 

My dad is insisting that I get the part numbers and that there should be two. Beyond a certain point I don’t ask more questions and just go along 🤗😂

 

Please do by all means teach me as appropriate if you will - assume I have near zero practical knowledge but extremely strong scientific underpinnings… or to put it another way, I know almost nothing about actual engines but could build an ICE from first principles if sent back in time 🤪😉

 

The actual fault being thrown is DPF showing as needing regeneration but not actually regenerating (even when manually set to do so via VCDS and run at the stated 2000+ RPM cruising at 70ish for upwards of an hour), then within another hundred miles hitting workshop fault and limp mode. Tricking it clear via VCDS gets about 500-600 miles of running no issues then exactly the same - except for the last time after an oil and filters change when it went 1200 odd miles prior to the same sequence.

 

The vehicle is my daily drive but owned by my dad - hence why he gets the call on work like this; I’d absolutely not have tried deleting the DPF ages ago if it was mine as that would be naughty 😅🫣

 

thanks for the advice and part list already provided and in advance for any future suggestions etc! 🥰👍🤗

Also am I wrong to think the quoted £180 odd for a SENSOR is way OTT or is that normal? 🫣😱

Lambda and oxygen sensor are interchangeable names for something that measures oxygen content of the exhaust gas.  This may be used to fine-tune the combusted mixture in a petrol engined car, or to help control various emissions after-treatment kit in a diesel engined one.  Exactly how the lambda sensor in a CAYC is used isn't something I know.

 

Differential pressure sensor is sensing the pressure difference upstream to downstream of the DPF. This can be used to infer the 'fullness' of the DPF.

 

Genuine VW group sensors can be spectacularly expensive. Be happy that your car probably doesn't have NOx sensors, they would be a lot more.

 

As for how to proceed; you say 

14 minutes ago, DeviantChild said:

The actual fault being thrown is DPF showing as needing regeneration but not actually regenerating

 but is VCDS picking up any stored fault code numbers, and if so what are they?

 

Could you please clarify the age of the car? You have CAYC as engine code in the thread title, but 2017 as the year in your profile, which would be a mk3 Fabia, and probably not a CAYC.

Reg number or VIN would help me to offer definitive part number info for any given sensor.

3 minutes ago, Breezy_Pete said:

Lambda and oxygen sensor are interchangeable names for something that measures oxygen content of the exhaust gas.  This may be used to fine-tune the combusted mixture in a petrol engined car, or to help control various emissions after-treatment kit in a diesel engined one.  Exactly how the lambda sensor in a CAYC is used isn't something I know.

 

Differential pressure sensor is sensing the pressure difference upstream to downstream of the DPF. This can be used to infer the 'fullness' of the DPF.

 

Genuine VW group sensors can be spectacularly expensive. Be happy that your car probably doesn't have NOx sensors, they would be a lot more.

 

As for how to proceed; you say 

 but is VCDS picking up any stored fault code numbers, and if so what are they?

 

so if I understand correctly - there are separate differential pressure sensors either side of the DPF and a single oxygen sensor AKA lambda sensor for this particular engine?

 

I’m hearing “find generic or pay through the nose” regarding the price, or is that disreccomended in this context? 🫣

 

regarding VCDS and stored fault codes, I want to say no but may well be pressing the wrong buttons (ooh lookie so many BUTTONS!! 🫣🤪🤩) so if you would be so kind as to send me exactly what to click/mash/press in what order to get the output you need I will do that and get back to you imminently 😇

 

once again MANY thanks for your time and kind assistance, it is very much appreciated! 👍😁

One differential pressure sensor only, I think, with one  hose connection upstream of DPF, and with it's other connection downstream of DPF or left open to atmosphere (because exhaust pressure after DPF is naturally close to atmospheric). Sensor may be visible near top rear of engine bay if you can pop a photo up.

 

The 'Fault codes' button when connected to control module 01 (engine ECU) should give you any stored codes.

See first three images here: Guide: Check Your ECU/TCU Box Code & Software Version - Audi/Volkswagen Fault Codes button just under where it says Basic Functions in third image.

 

2 minutes ago, Breezy_Pete said:

Could you please clarify the age of the car? You have CAYC as engine code in the thread title, but 2017 as the year in your profile, which would be a mk3 Fabia, and probably not a CAYC.

Reg number or VIN would help me to offer definitive part number info for any given sensor.

I have no clue how that ended up on my profile tbh 🫣🤦‍♀️

 

it is a 2010 mk2 Fabia estate, CAYC engine confirmed - 1.6 diesel tdi lump at the highest output of the three available variants (wanna say 105PS but that’s top of my head not checked), registration KN60 EJX (if I am not allowed to post that I apologise, I would have thought that was considered public information as compared to VIN but am doubting myself as I type this!); if you want me to check via VCDS or would like me to send you a picture of the VIN or full code/spec label in the boot floor space or any other way I’m perfectly happy to do so btw!

I can find VIN from reg, so that's enough info. 👍

Skoda dealers have an RRP of £233 + VAT for the lambda sensor for your car (same part number as in LLL link) so you definitely don't want to be buying one of those from  them without very strong evidence it is at fault!  I've never heard of one being discussed in the context of DPF regen problems, to be honest.

 

Will look up pressure sensor info later, just about to hit the road for a while.

 

Try to grab some fault codes with VCDS.

 

 

 

2 minutes ago, Breezy_Pete said:

One differential pressure sensor only, I think, with one  hose connection upstream of DPF, and with it's other connection downstream of DPF or left open to atmosphere (because exhaust pressure after DPF is naturally close to atmospheric).

 

but that makes too much sense! That isn’t allowed in automotive design! There could be another hose and coupling that would add a failure point and cost hundreds of beer tokens to replace!!

</sarcasm >
 

 

2 minutes ago, Breezy_Pete said:

Sensor may be visible near top rear of engine bay if you can pop a photo up.

will provide such photographic evidence as soon as my anxiety lets me go outside to play for a bit 👍🫣

 

2 minutes ago, Breezy_Pete said:

The 'Fault codes' button when connected to control module 01 (engine ECU) should give you any stored codes.

See first three images here: Guide: Check Your ECU/TCU Box Code & Software Version - Audi/Volkswagen Fault Codes button just under where it says Basic Functions in third image.

 

Yay me I was doing it right already!

 

I think. 
 

will do it again to be sure though 😁

 

I should have a stored set of “everything I could find to save everywhere” from before I went fiddling with things - let me know if that helps and I’ll go hunting for it 🤫🫡😅

 

all the thanking once again 👍😎

 

oh and you replied again already!

8 minutes ago, Breezy_Pete said:

I can find VIN from reg, so that's enough info. 
 

 

 

Which response also indicates I didn’t break any rules posting my registration, coolio happy days etc 🙃😅🫡

9 minutes ago, Breezy_Pete said:

Skoda dealers have an RRP of £233 + VAT for the lambda sensor for your car (same part number as in LLL link) so you definitely don't want to be buying one of those from  them without very strong evidence it is at fault!  I've never heard of one being discussed in the context of DPF regen problems, to be honest.

 

Will look up pressure sensor info later, just about to hit the road for a while.

 

 

from your description, the sensor I can see screwed directly into the exhaust pipe (it’s after the “fuel go bang - intentionally explody” bits so exhaust pipe by my reckoning lol) at back of the engine bay would be the oxygen sensor then? And NOT likely related to DPF fault? 
 

as in that case I’m so glad I asked and you took the time to teach 

 

would have been an expensive lesson to learn otherwise 🫣🥹😂

9 minutes ago, Breezy_Pete said:

Try to grab some fault codes with VCDS.

 

 

 

Wilco Roger. Or is that Roger Wilco?

 

Also read you 5x5 and other such amusingly accurate yet pointless in this format radio codes* 😁 

 

again massively appreciate the time and effort spent responding to me in this kind of detail btw😎👍🤩

- J

 

*If you are asking “why?” To this nonsense… I will say only “because!”

Exhaust system will have a bit of a littering of sensors including about 3 temperature sensors, so I wouldn't be able to readily identify the one you are describing. 

Your 'pressure difference sender' has part number 059 906 051C.  Check search engine results for images thereof. 

Have been known to suffer heat damage.

Fault codes would be helpful though.

 

How many miles has it done, and what's the typical usage pattern (lots of short trips?).

Edited 5 December, 20241 yr by Breezy_Pete

4 hours ago, DeviantChild said:

The actual fault being thrown is DPF showing as needing regeneration but not actually regenerating (even when manually set to do so via VCDS and run at the stated 2000+ RPM cruising at 70ish for upwards of an hour), then within another hundred miles hitting workshop fault and limp mode. Tricking it clear via VCDS gets about 500-600 miles of running no issues then exactly the same - except for the last time after an oil and filters change when it went 1200 odd miles prior to the same sequence.

 

Certain conditions have to be fulfilled for a VCDS driven regeneration which has the options of a driven or static one, engine temperature, fuel level etc.

 

I tried doing a forced regen 2 days ago and it refused saying ERROR  conditions not met or request sequence error which is as much help as a chocolate teapot, I had the same trouble with the routine for purging air from the injection system.

 

And yet if too many regen attempts are foreshortened it will try and regen the next day on a cold engine as soon as you start it!

 

There are so many parameters for the DPF most of which are for other vehicles and show nothing, the terminology changes all the time as well just to add to the confusion, these are the ones I select when looking at live data on my engine but I have to scroll through thousands to find them, this time I took a photo to make it easier next time.

 

Particle filter: difference pressure (not a typo!)

 

DPF: Offset for differential pressure

 

Particle filter: soot mass calculated

 

Particle filter: soot mass measured

 

Particle filter: oil ash volume

 

Particle filter; kms since last regeneration

 

You can see the differing terminology, your oil ash may well be measured as mass and probably have the wrong units stated.

 

The kms are actually shown as metres.

 

Regens are triggered on calculated and not measured values, frequently the measured are far lower.

 

On my vehicle they are triggered at a calculated 23 grammes, there is a higher threshold 35g??? where it then has to have a forced regen if you can actually get it to work, and a higher one still 40g????????? where it will not allow anything but replacement, for the life of me I cannot understand why a non blocked filter showing low measured back pressure would have to be replaced because of a wildly pessimistic calculated reading.

 

 

By "tricking it clear" do you mean selecting the option to say the DPF has been replaced?

 

I also did that but I believe it can lead to problems.

 

Come back to us with your readings from the parameters above at both tickover and high revs which might be limited to 2500 rpm at standstill, my DPF is somewhat clogged now from using the wrong oil so I know what a high reading is compared to what it used to be, I found it very hard to get any concrete figures on the internet not helped by the multitude of different units of measure.

On 05/12/2024 at 20:09, J.R. said:

By "tricking it clear" do you mean selecting the option to say the DPF has been replaced?

 

mmmmmmaybe 🫣🫡
 

On 05/12/2024 at 20:09, J.R. said:

I also did that but I believe it can lead to problems.

 

Come back to us with your readings from the parameters above at both tickover and high revs which might be limited to 2500 rpm at standstill, my DPF is somewhat clogged now from using the wrong oil so I know what a high reading is compared to what it used to be, I found it very hard to get any concrete figures on the internet not helped by the multitude of different units of measure.

watch this space- I’m outside for the first time in a week or two today and playing pretend mechanic 🤪 so will see if I can get readings before anything catches fire!

 

fingers crossed 🤭😅🫥

On 05/12/2024 at 17:59, Breezy_Pete said:

Your 'pressure difference sender' has part number 059 906 051C.  Check search engine results for images thereof. 

Have been known to suffer heat damage.

Fault codes would be helpful though.

 

FOUND IT !! 
 

Definitely helps to be looking for the correct thing and not a totally unrelated item… 

 

 

On 05/12/2024 at 17:59, Breezy_Pete said:

How many miles has it done, and what's the typical usage pattern (lots of short trips?).

143k miles - and unfortunately no idea as only had it since April @ 139K - and started throwing the described DPF faults about 500-600 miles later…

 

according to the ECU however it’s not ever had any faults prior - in other words the seller carefully wiped every log accessible to hide the issue 🤬🤯🤦‍♀️

 

promised a service was completed the day before my dad picked it up too… dunno WHAT they serviced though as we replaced oil and oil, air and fuel filters the other day and they were proper nasty 😕

 

currently trying to get access to the damn sensor wiring sufficient to connect meter and test it 😅🥲😵‍💫

On 05/12/2024 at 20:05, J.R. said:

 

Certain conditions have to be fulfilled for a VCDS driven regeneration which has the options of a driven or static one, engine temperature, fuel level etc.

not got the option for static on mine 😭

 

and the driving one doesn’t work for me so far - hence why I’m looking at other things rather than the DPF itself after multiple attempts (and wasting nigh £200 of fuel driving for hours on the A14, at night, so as to keep revs at required minimum CONSTANTLY 😕🤦‍♀️)

 

On 05/12/2024 at 20:05, J.R. said:

I tried doing a forced regen 2 days ago and it refused saying ERROR  conditions not met or request sequence error which is as much help as a chocolate teapot, I had the same trouble with the routine for purging air from the injection system.

 

And yet if too many regen attempts are foreshortened it will try and regen the next day on a cold engine as soon as you start it!

 

There are so many parameters for the DPF most of which are for other vehicles and show nothing, the terminology changes all the time as well just to add to the confusion, these are the ones I select when looking at live data on my engine but I have to scroll through thousands to find them, this time I took a photo to make it easier next time.

 

Particle filter: difference pressure (not a typo!)

 

DPF: Offset for differential pressure

 

Particle filter: soot mass calculated

 

Particle filter: soot mass measured

 

Particle filter: oil ash volume

 

Particle filter; kms since last regeneration

 

You can see the differing terminology, your oil ash may well be measured as mass and probably have the wrong units stated.

 

The kms are actually shown as metres.

 

Regens are triggered on calculated and not measured values, frequently the measured are far lower.

 

On my vehicle they are triggered at a calculated 23 grammes, there is a higher threshold 35g??? where it then has to have a forced regen if you can actually get it to work, and a higher one still 40g????????? where it will not allow anything but replacement, for the life of me I cannot understand why a non blocked filter showing low measured back pressure would have to be replaced because of a wildly pessimistic calculated reading.

 

 

 

Yeah regen doesn’t trigger AT ALL 🤯

 

even when set to run next ignition cycle - and yes it TRIES to run, takes out of limp mode correctly every time it’s set 🧐🙄😔