# EVAP System Charcoal Canister



## NotTayyeb (Dec 14, 2019)

I have recently noticed a fault code on my TT - P0441 - Evaporative (EVAP) Emission Control System, Incorrect Flow.

Two possible causes for this are the N80 valve, and the charcoal canister. Seeing as my car is about 12 years old, and neither of the 2 look like they have ever been changed, I thought I might as well change the pair.

Anyway, the with the charcoal canister, I believe the part number is 1K0 201 801E. However, I am seeing 2 variants of this part, and am unsure if this is just a revision? There is a part with the same part number, but an extra pipe facing down.

See below a picture of the aftermarket canister I have found;









And then have a look at 35 seconds into the following youtube video - this part does not have this extra pipe?





Anyone know why there is a part with the same number, and an extra pipe? Has anyone used this version with extra unused pipe?

Cheers!


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## Wolvez (Jun 22, 2018)

That's the canister vent. The one that don't have a pipe only have a hole. The purpose of that vent is to prevent vacuum getting applied to the fuel tank to prevent it from collapsing. When N80 is purging air is pulled from the vent.

Blowing compressed air to the canister can solve the problem. Make sure the canister is inverted to remove the dirt build


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## NotTayyeb (Dec 14, 2019)

Ah awesome, makes sense! A local parts store seems to have one with the vent pipe in stock, so will give it a go as soon as the N80 and some jubilee clamps arrive. Cheers for your help Wolvez!


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## MT-V6 (Jan 11, 2015)

Amongst the Chinese, the part number shown in that photo is for a D revision part

I'd be wary buying an unbranded part, because without taking it apart you will not know how effective the filter actually is, therefore letting dirty air back into the engine


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## NotTayyeb (Dec 14, 2019)

MT-V6 said:


> Amongst the Chinese, the part number shown in that photo is for a D revision part
> 
> I'd be wary buying an unbranded part, because without taking it apart you will not know how effective the filter actually is, therefore letting dirty air back into the engine


Well spotted! However, I think I might just use the Chinese unit which is £12, compared to the genuine Audi one which is around £70. £12 is worth biting the bullet on I guess...


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## MT-V6 (Jan 11, 2015)

The engine is a significantly more expensive thing to repair, but up to you. I'd always stick to OE quality parts from trusted suppliers


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## NotTayyeb (Dec 14, 2019)

I suppose I really should get an OEM part considering its feeding directly to the engine.. Just got a price back from the local indie that sell parts from TPS, they are quoting £110.89 + VAT for a cannister and hose!! That's no labour, just part cost. Ouch!

I will put in the Chinese unit today as a temporary part to get rid of the fault code, and will look to getting an OEM cannister, ideally when it isn't close to £130 all in.. What would be the other options to source an OEM cannister?


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## SwissJetPilot (Apr 27, 2014)

Just my two cents, but unless you have a habit of over filling, the charcoal canister probably isn't fuel-contaminated. This is more of an issue for the North American models as the canister is located under trunk (boot). So overfilling is more of a problem for that version, not the engine bay mounted version we have in Europe.

I'd start by checking/replacing the N80 first, then clear your faults and check it again.

If it turns out that it is the canister, shop around. You might be able to find a good used one off eBay for much less. Try to get one from one of the last production years so it should have plenty of life left in it.

Here's a video on the N80 Evap Valve that might be worth watching and a How To from the Forum KB -

*How The VW Evap Purge Valves N80 Fail*





*How to: Audi TT Mk2 (8J) EVAP Faults N80 & EVAP Canister*
https://www.ttforum.co.uk/forum/viewtop ... &t=1850235


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## Wheelnut (Apr 27, 2016)

In the days before warning lights spoilt everything, it was a common mod on some engines to chuck the cannister away and vent to atmosphere, thereby saving weight and complexity. It doesn't do anything particularly useful, after all.

Did this on my trackday MX-5, as did many others.

As has been said, the fault is most likely the N80. Many sensors and suchlike (and there are loads of them) tend to fail after about 10 years on VW/Audis.

Definitely hold off buying a new canister until you've checked the valve.


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## NotTayyeb (Dec 14, 2019)

Okay so. I replaced the N80, cleared the fault code and went for a spirited drive, but the code came back after said drive.. Changed the cannister to use the new Chinese replacement unit. Again, cleared the code and went for a drive, but this time the code has not come back, so it does look like the canister is the culprit. So now I search for an OEM cannister to replace my Chinese unit I guess.

I do have the habbit of filling the car past the 1st click at the petrol pump though, so maybe I did contaminate the canister... It's something I used to do on my state of the art Peugeot 107 because in the owners manual for that it said I could fill to the 3rd click, but not past that. I had no issues on that. Though shame on me for treating a TT like a Peugeot 107...


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## hectorechav (Apr 12, 2021)

SwissJetPilot said:


> Just my two cents, but unless you have a habit of over filling, the charcoal canister probably isn't fuel-contaminated. This is more of an issue for the North American models as the canister is located under trunk (boot). So overfilling is more of a problem for that version, not the engine bay mounted version we have in Europe.
> 
> I'd start by checking/replacing the N80 first, then clear your faults and check it again.
> 
> If it turns out that it is the canister, shop around. You might be able to find a good used one off eBay for much less. Try to ]


What are your thoughts about using a non-OEM canister from Oriley's (huge us auto retailer)? It has lifetime warranty and I just can't get on board with shelling out $150 for the Bosch one from Audi. I've had multiple mechanics tell me its fine to run the car with the code coming up on the dash (P0455) and that its more of an emissions regulation code rather than a critical engine fault, so again I'm not too keen on needing the OEM...

Regardless I would love your input. I used your guide on how to solve the grounding issue for the tail lights for the TT MKII. You are incredible for putting that together so well.


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## FNChaos (Nov 30, 2016)

hectorechav said:


> What are your thoughts about using a non-OEM canister from Oriley's (huge us auto retailer)? It has lifetime warranty and I just can't get on board with shelling out $150 for the Bosch one from Audi. I've had multiple mechanics tell me its fine to run the car with the code coming up on the dash (P0455) and that its more of an emissions regulation code rather than a critical engine fault, so again I'm not too keen on needing the OEM...


Personally, the vapor canister is one of the few emissions components I would have no problem experimenting with aftermarket (as it's nothing more than a plastic container filled with activated charcoal) *IF* (and this is a big _IF_) the canister was mounted in the engine bay... But as SJP pointed out, US vehicles mount the canister underneath the rear of the vehicle (approx below where the spare tire well is located). Access requires you to drop the back half of your exhaust and remove a heat shield.

Not that any of this is particularly hard, but IMO the time required to do it twice (should your aftermarket part fail to perform) is worth more than the money saved by going with an aftermarket part.

Note: P/N for a *US vehicle* should be 8J0201797D not 1K0201801E as listed at the top of this thread.


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## SwissJetPilot (Apr 27, 2014)

@ *hectorechav* - The *Charcoal Canister* used on US Models is a different design and located inside the hump under the trunk and not in the engine bay like the European models. If the aftermarket one is the same design, it should work just as well. I would imagine O'Reilly, PEP Boys or Auto Zone should carry them.

Please read the attached *Technical Service Bulletin* (TSB) for *Recall Campaign 20Q3 for 2008-2010 TT Coupe and TT Roadster* as it includes work on the Charcoal Canister. Depending on your year, you may want to discuss this with an authorized *Audi Service Center* to see if your vehicle is included. It will also give you a good idea of the work involved as *FNChaos* mentioned above, there's a few things you'll have to get out of the way first.

View attachment Audi_TT_Recall_20Q3_Fuel_Tank_Ventilation_Valve.pdf

If you need an additional reference, it's covered in the *Workshop Manual* linked below -

*FAQ - Audi TT (8J) Workshop Manuals & Self Study Programs*
*Fuel Supply System, Petrol Engines A005TT01020*
https://www.ttforum.co.uk/forum/viewtop ... &t=1833829


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## Rufflesj (Jun 22, 2020)

Cheap aftermarket version works fine on mine, it's not a technical part, just a plastic container with charcoal in it.


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## chrisj82 (Jun 15, 2012)

I put a cheap canister on mine and you can see where they scrubbed/ melted the audi vw symbol off.its been on for nearly 2years with no problem


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## NotTayyeb (Dec 14, 2019)

My Amazon charcoal canister has been working okay too, I've not had any reoccurring fault codes encouraging me to get the OEM part. @chrisj82 mine has the scrubbed off Audi logo too - I wonder why they do that, could they be ghost shift parts potentially?


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## chrisj82 (Jun 15, 2012)

Could be?here is a pic of mine you can clearly see where the audi and vw has been scrubbed off.


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## SwissJetPilot (Apr 27, 2014)

Just grab a hair dryer and blow it out. Be sure you have a lit cigarette handy while you're doing it. Because - vapors.


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## IPG3.6 (Sep 5, 2015)

Remember there is another check valve after the N80 that still may be causing you issues.

I've recently had to fix this error on a MK5 GTI (AXX) and luckily it was just the N80 as SJP has pictured. I was almost ready to remove the inlet mani to get to the other valve which is UNDER the inlet manifold and bolted down with a T30 Torx screw.

It is #18 in the schematic. PN 06F 133 781 L - i'm not sure why it says blue, my spare one from the TT's 2.0 BWA is definitely black.

If you've changed both the charcoal canister then the N80 (both the easily accessible parts) then I'd be suspecting the one way check valve is next in line to replace.


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## IPG3.6 (Sep 5, 2015)

This is what I'm talking about. The check valve underneath the 2.0 inlet manifold. It's much more easily accessible in the 3.2.

EVAP system components and what to replace when you have a P0441 incorrect flow error


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## Rufflesj (Jun 22, 2020)

Good to know, I still have the tiniest little misfire on idle but no codes, recently put a Febi PCV on and my lean code went away. Also had replaced the cannister and N80 just previous to that, wondering if that could be the final nuisance? I'm guessing that's an inlet off job on the BWA? Cheers.


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## Wolvez (Jun 22, 2018)

Maybe your using Iridium spark plug instead of platinum? Try upgrading it to latest Ruthenium Spark Plug to make the engine idle more smoother. It also make the engine start faster. I'm trying to release the key as fast as I could but the engine always starts when using ruthenium.


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## IPG3.6 (Sep 5, 2015)

Yeah it's so tucked away it would be mani off job.

Never heard of these style spark plugs Wolvez. Might look into them when the time comes for the VR6.


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## Rufflesj (Jun 22, 2020)

Wolvez said:


> Maybe your using Iridium spark plug instead of platinum? Try upgrading it to latest Ruthenium Spark Plug to make the engine idle more smoother. It also make the engine start faster. I'm trying to release the key as fast as I could but the engine always starts when using ruthenium.


 I put NGK Laser Platinum 1675 PFR7S8EG in it in Feb. I had Bosche iridium in before that. Will look into ruthenium, cheers.


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## Rufflesj (Jun 22, 2020)

Had a read up on the ruthenium plugs. The car def improved when I switched from iridium to platinum (although I did change the PCV at the same time) and from what I'm reading, ruthenium seems to be another step up of improvement. Having owned an Alfa TS and several Fireblades I always thought that the whole iridium thing was related to longevity as the aforementioned are a complete and utter pig to change plugs in (3hr DIY job on 929/954 Fireblades!!), obviously platinum has been an advance on iridium in latter years.

I'll know by next Mon whether I'm changing up or tuning the TT, I'll def give the ruthenium a shot if keeping the car.


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## Tom Tim Smith (Oct 3, 2021)

after reading an item on here when I got the P0441 code I remembered I had just checked my oil level (2012 mk2 TTS) on checking the dipstick the O-ring had slipped down the shaft , after replacing it the code didn't come back; the item I read said basically a loose dipstick or missing o-ring could lead to incorrect flow as air would more likely enter the engine through the dipstick hole than through the evap canister so check the dipstick first before chucking away a load of money, the o-ring on the TTS is not in a groove so can fall off easily


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## EssexRob (Nov 7, 2021)

NotTayyeb said:


> I have recently noticed a fault code on my TT - P0441 - Evaporative (EVAP) Emission Control System, Incorrect Flow.
> 
> Two possible causes for this are the N80 valve, and the charcoal canister. Seeing as my car is about 12 years old, and neither of the 2 look like they have ever been changed, I thought I might as well change the pair.
> 
> ...


Having had problems with the EML light appearing on the dash and having changed the purge valve I decided to change the charcoal canister as it was the original 14 year old part and reading this thread the pipe supplied with the canister wasn’t anything like what’s fitted to the car. I ordered an OEM canister and the vent hose supplied with it is exactly as expected. If anyone is interested the part number for the hose is 8J0 201 160 C Part number for the canister is 1K0-201-801-E


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## SwissJetPilot (Apr 27, 2014)

@ *EssexRob* - Can you post another few pics when you have it connected and installed?


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## EssexRob (Nov 7, 2021)

SwissJetPilot said:


> @ *EssexRob* - Can you post another few pics when you have it connected and installed?


Will do 😊


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## EssexRob (Nov 7, 2021)

SwissJetPilot said:


> @ *EssexRob* - Can you post another few pics when you have it connected and installed?


Changing over to new canister and vent hose was a simple 10 minute job. Appeared to be lots of loose carbon granules in the top of the canister but otherwise unable to tell what condition it was in. Seems to have fixed the problem though. Here are a few pics as requested, include one looking into the old canister.


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