Former

Why do you leave the car idling for 4-5 minutes?

I'll take your word for it, you offer an explanation and example including a strange word (though that might be from pdf lift) very much the standard in the Manuals. Confusingly for me my wife's manuals are 'Operating Instructions' for the car and 'Owner's Manual' for the infotainment, I'm sure it can't be a mistake as car companies don't make mistakes especially when German efficiency and German Engineering is involved. I only guess that best practices, and perhaps material and parts supplies, change with time so the manufacturers change their recommendations, I'll exclude mistakes for the reasons above, what they put in a 2015 manual may be different to say a 2017 manual. It is from me. I've changed my wording to some manuals based on your info, thank you. Only Skoda/VW might know, VW particularly has in the past found to be particularly tight-lipped about some of there goings-on - but I'm sure Skoda/VW welcome all customer enquiries, getting a response or answer my be a different matter.

Have you checked your coolant sensor and perhaps your coolant thermostat? Do you regularly change your coolant? What coolant do you use? Why do you leave the car idling for 4-5 minutes? 0c isn't cold for 10w, do you change the engine oil & filter in a timely and regular manner?

Don't assume, check and at least double check instead. Are you sure they are exhaust fumes and if so that they are coming from where you think and not elsewhere, don't assume. If you're changing that part anyway you'll find out when the old parts is off the car as you should see evidence and when the new part is fitted it should resolve that problem if it was present.

cheezemonkhai, is your machine's figures are accurate I think given a longer, lower, slower recharge after depleting its present charge the battery might be good for use. A way to deplete it might be a drop test like cranking over an engine that has been prevented from starting to see how quickly the battery drops. If the battery wasn't good enough to start your diesel on a cold day that hasn't been started for a few days (assuming it's a correct size battery for your car needs) then it might be loose or crudded connections or wire elsewhere also not helping the battery so you might want to do a quick check. I won't suggest it was the old grease on the old battery's post. 🤣 I can't remember, did you also check test the alternator just in case?

Yes I did too, some say you don't need to, others even say you shouldn't but I did and the car and I came out of it unscathed. as some were so against such a thing I contacted Tayna to check and they said it was fine. Some also said I should not have used my 20 year old Accumate (or my 30 year Bradex BX4 (amp)) I can't remember if I checked this with Tayna or not but I would have put it in my post if I did. The Liqui Moly Battery Clamp Grease is for the job but would probably be of better use in wire plug connectors. - https://products.liqui-moly.com/battery-clamp-grease-3.html The MG Chemicals 8481 - Premium Carbon Conductive Grease seems to me to be a switch/rotate lubricating grease which would probably work but I'd ask MG Chemicals which of their many products they'd recommend for car use you'd probably get a long list unless you spoke to a tech on the phone and just asked them to suggest one. - https://www.mgchemicals.com/products/grease-for-electronics/electrically-conductive-grease/conductive-grease/

That sounds similar to what we had driving on 1 mile of some very new tarmac smooth road surface. In Northamptonshire and Leicestershire we had countless resurfacing with the chippings, started decades back, surface-dressing to save money, what a laugh it had to be done so often iron work and even kerb stones had to be raised as one layer went of top of another. Then when it isn't attended to the holes get wider and deeper and multi-layered. Having driven on the chippings for so long you get used to it - then we get on to this super smooth bit of new tarmac and its quiet until I notice the noise similar to your recording. Once back on the chippings you realise how rough the surface is and the different noises from it, for a short while then it's as normal. BTW Cotic if you add Fabia Mk3 1.2 TSI SE L (manual) (Year: 2015) to your details it'll save having to remember and help with answers. Also 'summer tyres' (or tyres as they used to be called) start to lose efficiency at IIRC 10c (a summer's day in Scotland I believe) hence the Crossclimates and Winter tyres.

cheezemonkhai just for info, modern batteries haven't needed their post protecting to the terminal clamps for quite a number of years but don't loose sleep over it. If you remove the terminal clamps for any reason in the future you can wipe the inside of them and the battery posts clean. You can buy a tool for cleaning the battery posts and inside of clamps but you should need to do much cleaning on the posts of a new battery anyway. Lots of garages spray over the top of the battery clamps and posts but as xman has already put not necessary and put good for collecting dirt/crud/ muck/grit. For battery figures of Ah and CCA you do have to also consider for how long and how well any given battery will keep to its figures as stated at new so a bit of research, calculation of other info given, trust, guesswork, reputation and hope involved. I've attached a PDF of different standards to measure CCA as there might be variances in other countries, usually EN here but also note the DIN in fabdavrav post. As I discovered with a neighbour's old Merc, Halfords can have their own system of battery numbering if you use their database, as my neighbour did and then didn't want me to cut off the additional level of plastic foot hold down bar, 30 seconds work, so I spent 30 minutes altering the clamping plate instead. Batteries and charging don't like the cold or hot, some chargers also have a winter setting for when the temperature will be below 5c as well as AGM setting. Your CTek MXS 7.0 is fully set for AGM going from -20c to +50c. At 7 amp it's quick but note Yuasa recommend 4 Amp so you'd be better perhaps, when required, putting the charger on at nearer 4 weeks than 2. As with the battery figures the highest numbers aren't always the best. I always recommend a long low slow recharge as possible rather than faster especially if the discharge was long, low and slow. Sounds like you already have a separate battery analyser but you can also get combined smart charger with battery analyser. The 12.7 wasn't necessarily fully charged but it does depend on what figure your machine usually gives (can be 12.8v or 12.9, my digital multimeter will show well into 13 on my car even after surface discharge). Hope this is useful with your battery changing guide. Cheers. CarBatteryInformation.pdf

You don't say! That doesn't indicate you've read the post or attempted to answer the question. Thanks for passing by though. YOU asked - You are probably stressed and upset with yourself but there's no need to be that rude, it seems to be catching here, unfortunately it often seems those dishing it out can't take when inbound. So take a breath, and ignore this post if you want, or even bigger breath before replying, no need to thank me though. 😁 I was going to answer but I see roottoot has given an explanation to this already and other help, KeithCheetham has given you great help - you asked for help and it has been given. Unfortunately this is the only help I'm able to give you on this subject at the moment, good luck on sorting it.

Not wishing to rain on your parade but do be sure to cross reference any information you get, from anywhere, but especially databases as the originals can have errors and omissions which can be copied and often added to. Check the engine type you have, there might also be numbers on stickers and plates on your car. Also check the part is correct to the engine you have. It's not unknown for even garages to fit wrong parts based on the databases they use. And never assume a part fitted to your car is original correct just because it's fitted and working. Good luck.

Nivek74, if you've tested the battery which it sounds like you might have, new battery is just a store so can be depleted, you've tested the alternator so if the battery has good charge then any other codes or info from the scan tool or symptoms - otherwise you might be heading for a big spend. And possibly worst still there'll be, even more, celebrations, and braggartry, in Brighton. Good luck anyway.

Do you know, or are those assumptions, might be a rare slip from good manners.

No No ?

Nivek74, having had a quick look at the code you won't want to be driving the car with that code so if the battery is low you might as well take it off and give it a long slow low recharge to allow for starting and stalling difficulties, unless you're getting it repaired at home or trailered to a garage. I could well be wrong but I'm guessing you won't be doing the the crank sensor swap out, if needed, yourself.

Nivek74 put your registration into a car parts suppliers search on their site and it will give you the info, assuming it's the same for NI you could try Euro Car Parts or Opie Oils or others. I just copy the info and keep back up records and then just forget it. I'll say what I always say make sure it's not with your car battery being in a low state of charge, just because it starts the car and the lights seem bright enough doesn't always mean the battery's not too low for the computers to throw wobblies and anyway you want a good state of charge this time of year particularly if you've got electric and engine faults.

Yes anything that restricts the air getting to and through the radiator or to the engine particularly in a hot country will not help with cooling and running.

Many apologises I totally misunderstood your purpose, been adopting the attitudes of posters from the other forums too much, associated information, I like to post similar. Carry on , thank you for doing so.

circumlocution - the use of many words where fewer would do - yes - especially in a deliberate attempt to be vague or evasive. - NO

Pre-soak with a good penetrating/releasing agent for long as possible in advance of work (not WD-40 Mult-Use if you can PlusGas or GT85 is better, more uses). - https://gt85.co.uk/gt85-original/ - https://www.plusgas.co.uk/en-gb Clean or wire brush fitting as required. Soak again with good penetrating/releasing agent. Try to slightly tighten fitting first to crack rust/crud seal Then hopefully loosen, if not repeat from start - let the chemicals do the hard work.

Totally agree I can't keep up. Short answer - I didn't say to take the plugs out, in fact rather opposite. Longer answer - Plugs, wouldn't be my first thought to check especially if time is tight and has already been found getting the sensors out can take a bit longer than expected, but it's always worth knowing the plugs are as they should be, but I wasn't thinking of petrol or oil but that does raise a good point about new seals. My extended experience (of parts particularly) is - . parts can break or be faulty at any point (often from new in my case) . wrong parts can be sent and fitted . the correct part can be of the wrong material (I had a seal made of neoprene instead of Viton in a part, 20k units sold over 20 years and I get one of the very few (perhaps two) so the engine had to come out again to get at it, pence worth of rubber in reality, from a UK specialist motorsport engineering company) . new parts fitted are best suspected rather than dismissed because they're new . things can got wrong with parts fitting not noticed at the time . there can be more than problem in the same issue or there can be a 2nd (3rd, 4th, ... ) . this is DIY work so no cost per hour (or part of) or professional ego (it'll be this) time constraint, cutting corners, adding more parts for profit or to cover ego or poor diagnostics or arrogance . at this point only scan tool info is adding at short term fuel trim at idle (I've forgot now what was going on with exhaust sensors). There another quick post, I could write volumes on poor quality parts and work on just the cars I've had.

Unless there one that's odd I don't think the plugs will tell you much, if all have been on a rich idle they'll all show that but if one or all are worn, damaged or incorrectly gapped then that's worth knowing. As long as it's good quality why not. Your scanner should help with that decision but as well as the sensors you could screw in a pressure gauge front and rear to judge the cat - and aftermarket cats like other parts can vary in quality and longevity.

If it's a really good scanner does it not give value ranges and colour coding to like (but not) OK - suspect - bad (in green amber red perhaps), also could you record a report to, er, export to something that can be viewed a file, "print out" or "photographed". Again if it's got freeze frame at time of fault(s). Or perhaps a video of a live data stream at idle and if possible a second person driving. Have a read of that link I posted and do tick off all the things suggested that you've already done and those you haven't a to-do-list. Same thing for all the suggestions on this thread from the start do the lists and better to check twice than not at all. If it's a lot less hassle to fire the parts cannon again fair enough but I thought you put the other sensor showed as OK on the scanner. Again on a really good scanner you can test and activate things from the scanner (turn one headlight on to test it) forget the terminology, call it Timmy-two-ways for now.

Some scanners give a range but it doesn't matter as the values can usually be looked up, normal type figures range - but if you can put up all the info you can those that know can say. I don't know what scan tool you have but even the really low priced ones should give you the basic info subject to their programs and being relevant to your model and year. If you're not sure have a look at a few videos of your scan tool model, some are better than others and some you might gel with more than others, some have a knack of making things easy to follow and understand whilst others make the simplest operation way more complicated in their presentation.

Yeap, that get the light on. I've lifted below from a webpage, you might also want to read the page just to see if you've missed checking something before, link below (other webpages are available). "Diagnosing an engine that is running rich is really not that simple. It often requires some diagnosis skills if you do want to waste money on just replacing parts. - This is how a professional would do it, and you might need some extra tools to make it. Connect an OBD2 Scanner and check for related trouble codes. If you find any other trouble code regarding another sensor, start your diagnosing at the sensor. Check the live data values of the O2 sensor. Does it show that it is decreasing the fuel amount all the time? Then it is probably not any fault with this sensor. If you have access to one emission control tester or an external air-fuel meter, connect it, and check the actual air-fuel meter. If it shows that the fuel mixture is lean, while the O2 sensor is telling us that the engine is rich and removing fuel – there is a problem with your O2 sensor, and it needs to be replaced. Check the values of all the temperature sensors like the coolant and air temperature. Check the values of the MAF sensor or MAP sensor if you have one. Replace if faulty. Check the fuel pressure and ensure that the pressure is not too high on idle or on acceleration. Check the fuel pressure regulator or the vacuum hose to it if it is too high." Sorry about all the adverts but it's free advice so . . . https://mechanicbase.com/engine/engine-running-rich/

Well if the parts are of good quality and this is your second change then perhaps it the wiring or connectors or connection to whatever computer or problem inside the computer (or its programming) or sumfink else. Best if you can post up a freeze frame or live data report or list of all other error codes and see if those that know about these things (not me) can spot anything. What are your readings for pre and posts sensors, that might be a start? Did you hear and rattles or noises on the exhaust bit when you had them off the car or on those that stayed on the car?