# 03 A6 P0441 code question



## atgordon (Sep 3, 2009)

Have just acquired a 2003 A6 avant with 134k on the clock. When I bought it, it was reporting a 16825/P0441 code - (Check EVAP canister purge regulator valve). I cleared the code, and hoped that WD-40 on the gas cap seal might help! (I remember once reading that a number of gas purge/evap problems could be traced to poor gas filler cap sealing ...). It doesn't, and code is back after 200 miles.
Car drives fine so the issue doesn't affect driveability.
Anyone suggestions? Replace the purge valve?
Thanks, 
Tony
(off on a tangent ... are any of the Audi CD manuals listed on eBay for $10 worth getting?)


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## GLS-S4 (Jun 6, 2005)

*Re: 03 A6 P0441 code question (atgordon)*

Could try installing a new gas cap as it helped on my C5 A6.
I occasionally trap intermittent 16825 on both the B5 S4 and C5 A6 during winter months. A bit of moisture accumulates in the N80 purge valve, freezes and causes it to stick. Thawing the car and clearing the codes helps until moisture accumulates again. You can remove the N80 and try cleaning out the dirt accumulations and testing lines / coil resistance etc, otherwise last step try replacing N80 purge valve.
A bit more info:
http://forums.audiworld.com/ar....html


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## atgordon (Sep 3, 2009)

Thanks ... I'll try the new gas cap. I did search to see if I could locate the purge valve, and although I have narrowed it down to being on near the air cleaner, I'm not sure what it looks like beyond have two tubes and an electrical connection ... I'll have a poke around and see if I can locate it and see if I can clean it somehow.
Tony


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## GLS-S4 (Jun 6, 2005)

*Re: (atgordon)*


_Quote, originally posted by *atgordon* »_I'll have a poke around and see if I can locate it...

N80 Purge Valve is on top of airbox and in top left corner of this pic http://****************.com/smile/emthup.gif


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## atgordon (Sep 3, 2009)

Many thanks for thanks for the photo ... most helpful! I now know where the air cleaner is located as well!
I did remove the valve and gave it quick visual check (didn't do an ohm meter check yet), and cleaned it a little. It didn't allow air through in either direction (which is normal I believe).
I'll see if it throws a code in the next week ... if it does, I might have to invest in the Ross-Tech software so I can carry out the onboard test routine.
Tony


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## dangerous_dave (Jun 28, 2006)

*Re: (atgordon)*

most common causes for evap leaks are a bad gas cap, n80 valve or fuel in the charcoal canister. that happens when you top off your fuel at fill ups. the fuel goes past the check valve and enters the canister. they weight 5 pounds when new. i pulled one out of a car that weighed 10 pounds. that means there was 5 pounds of fuel in it. you should remove the canister and weigh it. if its over 5 pounds, replace it because you have fuel in it. you should replace the n80 valve and gas cap first though.


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## atgordon (Sep 3, 2009)

*Re: (dangerous_dave)*

Thanks Dave, I have replaced the gas cap, and checked the N80 valve (it appears to be functioning correctly), so I'm guessing that the EVAP canister needs looking at. Given that the car has 140K miles, probably not too surprising.
I have electronic manual (off one the eBay sellers) that shows where the canister is located (under the spare wheel well) and how to remove it ... but it does not give any information on how it can be serviced ... is that possible? I am assuming that the extra 5lbs of fuel that you noted in your email should be removable in some way? I found a Nissan forum that mentioned blowing compressed air at 45lb/in through vent line ...
Thanks Tony


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## atgordon (Sep 3, 2009)

*Re: EVAP canister*

Removed the canister .. weighs 5lbs (almost exactly!). No sign of fuel sloshing around when shaking it ... no carbon in the lines. Did hook up a low pressure line to blow air through it, but doubt if that would have done very much.
N80 valve next I guess ... I know that there is VAG-COM test that can be run (I've got V409.1)... anyone know how that is done? Tony


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## dangerous_dave (Jun 28, 2006)

*Re: EVAP canister (atgordon)*

just because the valve ticks when you turn it on with vag com, it doesnt mean that the valve is working properly. take that into consideration when you test it. You should take a multimeter and ohm it out. i can get you the spec for it if you IM me your VIN.
take the valve out and tap the part where the lines connect to it on a sheet of white paper. see if any junk comes out.


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## atgordon (Sep 3, 2009)

*Re: EVAP canister (dangerous_dave)*

Dave,
I have the specs for the purge valve for my model (I have an online manual), so can check it out. I had removed it once before to check basic ops (blowing through it when disconnected - didn't allow air through) and nothing came out when tapped on the ground (lightly). 
I'll check it with a DVM and see how it looks and will let you know.
Tony


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## dangerous_dave (Jun 28, 2006)

*Re: EVAP canister (atgordon)*

OK


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## Viola (Nov 2, 2007)

*Re: 03 A6 P0441 code question (atgordon)*

I have the same problem too.
I drive a 99 Passat 1.8T. A month ago, my car popped out a DTC of 16825 engine check light. Then it turned off by itself 4 days later after I got gas and turned my gas cap several clicks. However, it came back on 3 days ago. My gas cap was looser than usual so I tightened my gas cap a couple of times and it hasn't turned off by itself. I haven't sprayed WD 40 my gas cap seal though. I should give it a try. I'm doing all the things I can before I replace the purge valve because it is just bizarre that it turned off by itself and turns on again after a month.


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## dangerous_dave (Jun 28, 2006)

*Re: EVAP canister (atgordon)*


_Quote, originally posted by *atgordon* »_Dave,
I have the specs for the purge valve for my model (I have an online manual), so can check it out. I had removed it once before to check basic ops (blowing through it when disconnected - didn't allow air through) and nothing came out when tapped on the ground (lightly). 
I'll check it with a DVM and see how it looks and will let you know.
Tony

Call Audi and see if there is a TSB or RVU about reflashing the ECU for this code. The newer 3.2 A6 cars get alot of evap issues and there are reflashes available for it.


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## atgordon (Sep 3, 2009)

*Re: EVAP canister (dangerous_dave)*

Hi Dave,
I did a search and although it looks like there is a general reflash TSB out there for a lot of C5 models, but when I took the car in quoting what I had found, the Audi tech showed me the TSBs for my VIN and there doesn't appear to be a TSB for the ECM reflash C5 Avant with the 3.0L engine ... weird.
Just in case you have access to ELSA, i'll PM the VIN ...
Thanks, Tony


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## atgordon (Sep 3, 2009)

Have found out that this problem can also be caused by the failure of the evap test pump in the rear inner wheel well. (a friendly mechanic with access to IaTN repair database suggested that).


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## dangerous_dave (Jun 28, 2006)

*Re: (atgordon)*

You can check the test pump by running the evap test with vag com. its basic settings block 71 with the engine running. If the test runs, your pump works.


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