4Driver4

I remain skeptical about Gary's miraculous fix, but I have been able to duplicate it (sort of) and my light is now off for the time being. Since he has not posted to the contrary, I'm assuming Gary's car is good to go.

Here's what I did:

I disconnected the outlet hose and ran the 071 test. Fail.
No surprise.

Then I reconnected everything and ran 071 again. Fail.
So I ran the 070 test. Fail. This was a surprise, but the car had been passing this test prior to this.

Since I'm 16 months from my next emissions test, I put everything back together and returned the car to service. Two weeks later the CEL turned off.

After about a two weeks with no CEL, I checked codes and found the P2404 still there, but noted as intermittent. I cleared the code yesterday, drove the car 100 miles, and rechecked this morning. No codes, all readiness set.

I will continue to monitor...

frankinstyn

I was skeptical of this fix as well. I didn't even take mine apart. I simply ran the output test several times. I then ran all of the emissions system test and proceeded to drive it for about a month. A few weeks in, I check the emissions readiness and to my surprise it PASSED!

I've had this car for over two years with this problem and it has never completed the emissions readiness. I continued to drive it and the light hasn't come on yet (knock on wood).

The history:

Sept 2013..................purchased car
Oct 2013...................Light came on - P2404
Jan 2014...................Replaced purge valve (n80)
Jan 2014...................Replaced all emission system and vacuum lines
Feb 2014...................Replaced gas cap
Apr 2014...................Replaced purge valve (n80) with factory one from dealer
Sept 2014..................Replaced Emissions pump
Nov 2014...................Replaced charcoal canister
Dec 5th 2015...................Cycled Emissions pump several times using VCDS
Dec 7th 2015...................Found it had completed its emissions checks
Dec 16th 2015...................Found it had completed its emissions checks successfully again
Jan 5th 2016.....................Having driven it about 1000 miles, I've had no codes come up (knock on wood again)


I think that I just never made the computer realize that it had a new pump. I needed to force it to cycle in order to recognize it. I could be wrong but I don't care. I'm just so happy. I'd been clearing that code every day using the bluetooth OBD2 scanner and the Torque android app, and sometimes my computer.

I wish there were some sort of instructions mentioning this. I have the factory manuals and even they simply state to replace it without mentioning any software initialization.

Just Because I'm happy....here is a picture of my lovely car!

3.2l, adaptive air suspension, gps, running on euro 5570 mmi 2g high, almost nothing done to it.....135,000 miles



...and my more fun little restored diesel rabbit (1980 with a 1.9na swapped in)

4Driver4

Interesting.

Love the Rabbit!
I've got a 1980 Scirocco tucked away in my garage. Love those vintage VWs.

A6Gary

After seeing these recent postings, here is an update on this DTC for my '06 A6 Avant. The Check Engine light has not been tripped since I reported last. About two weeks ago, I got a TPMS warring while I was up at Crystal Mtn skiing. When I got home, I was using my VAG-COM to check and clear any TPMS errors, so I checked the Engine Module for DTCs. I again found the P2404 code but it was dated Nov 25th (over a month earlier). I cleared it and nothing since. I have no idea why the EVAP system seems to work as it should now based on what I posted earlier. However, I was checking the resistance for the N80 valve I replaced earlier and it read 18 ohms, which was below the Bentley Repair Manual stated acceptable range of 22-30 ohms, but it still worked. Given that result, I decided to order a factory valve and check its resistance. But the new valve measured 16 ohms, still below the "acceptable" range. So, the Bentley Manual must be in error for the test. In any case, I have left the system alone and hope that the dreaded P2404 stays off. Good so far!

occhis

I have an update as well on the elusive P2404 code from hell. I was forced to replace the battery last month, as it was the original 2006 vintage unit. It was to the point that it needed to be hooked to the charger unless the car was driven every 2 days, which doesn't happen. After replacing said battery, I noticed the CEL no longer stayed on. Hooked up the code reader and no active or pending codes. CEL has not turned off on its own for several years, but I am still skeptical that it will stay off. Have gone through at least 6 drive cycles and about 300 miles logged since the mysterious disappearance.
History tells me that it will likely be back, as I have gone months and over 2,000 miles for it only to return. Happy for now, though, hoping that somehow the new battery may have solved this long-running pain in the *** even though it has caused no functional problems. Planning to move to a county that requires emissions inspection and was worried that having that light on would be a reason for it to fail the test. Hope it's gone permanently.

milan_o

I have been enjoying driving lately and have recently acquired a blindness to a particular shade of orange especially when shaped like an engine. Then... I see this thread again! Now all I see is orange! I am going to finally continue my investigation into this.

First of all thanks for everyone posting updates. I will post updates with progress.

occhis

Well this time it lasted 559.1 miles before the demonic light made its re-appearance. This time it may at least partly be my own doing. I put gas in the tank from a gas can and it got a little messy. Just wonder if that was the root cause, as CEL came on during the second drive cycle after doing that.

ILLusive

any update?

occhis

Well I cleaned the snow screen and reset the fault code. So far no CEL but it really hasn't been driven much since then. Don't worry, I'll keep you informed the next time I get a light, as I fully expect will happen.

carlzimmerman

Ah yes - the P2404 code from hell. 2005 Audi A4 3.2L Quattro - Have had CEL code P2404 code since 2012! - and have been fortunate enough to find somebody to just pass my inspection until this year.

Here is what I have done:
replaced gas cap (recent)
replaced Evap Detection Pump (2013)
replaced P80 blowoff valve (2013)
smoke test performed 2014 - no leaks found



Potential fixes besides replacing ECM:

Small plastic tube that runs from the intake manifold down toward the dipstick and connects to a rubber hose on the left side of the engine. (this seems to have worked for some people on the forum temporarily) Part: https://www.ecstuning.com/ES2593921/

J757 relay under ecm replaced ( not sure if they are related - some people have replaced and no difference)

Gas canister replacement

Wiring

Have brought the car in to my local Mechanic today (who is absolutely AWESOME) and yes, indeed, it appears that I have a faulty ECM.

Exploring my options as far as having the ECM repaired ($1k) vs New ECM ($1.6k) vs Used ECM from wrecked vehicle (?), but I will be having it replaced.

Will follow up with an update on my status, but will be keeping my current car because A.) The hood lines on the new 2017 Audi's are quite ugly B.) I prefer the grumble of a straight 6 to the modestly quiet and fuel efficient 4 cylinder turbos. C.) I don't believe in financing anything - especially depreciating assets