View Full Version : Evap Purge Regulator Issue

04-25-2012, 02:37 PM
I have a 2001 A4 1.8T
I am having a problem with my Evap system. I have a trouble code P0441 for Evap purge regulator incorrect flow. I have spent many many hours trying to locate the problem without any luck. I have tested resistance on the purge regulator and the Leak detection pump according to my Bentley manual, and the ohm resistance is good.
I have traced the evap lines through out the engine compartment to the drivers fender to the Vacuum reservoir, the lines to the Leak Detection Pump, and the lines to the Evap canister under the trunk.
I dont see any obvious signs of cracking or failure anywhere.
I checked with Audi on any open Recalls, but none are open.

04-25-2012, 06:57 PM

04-25-2012, 07:14 PM
Just did a little searching, and it says you may have a clogged n80 valve. If you have a parts car laying around, try swapping it out. Other than that, I can only think to check the lines and check valves. But I'm rather perplexed because I have my n80 completely removed from the plumbing, and only electronically plugged in. Not sure if it is because of my tune or not, but no CEL. But swapping it out is a good thing to try out.

04-25-2012, 08:09 PM
I performed the ohm resistance test on the n80 valve, the resistance was within the Bentley Manual's range, so I am hesitant to replace it. Although, I do have another 2001 A4 1.8t that I could swap n80 valves with. I suppose that is my next step if nobody else chimes in with another idea.

04-25-2012, 08:12 PM
Never said the electronic part was faulty. The searching I did said it is a possibility the valve is clogged, causing the incorrect flow DTC. That's why I suggested you try swapping them out if you had a spare laying around. Free diagnosis on your side.

04-29-2012, 09:11 PM
I finally had the oppurtunity to swap the Purge Regulator from my other 01 A4 today. I ran the car through Vag-Com and tested the Purge Regulator, but it still failed the test. At this point I am stumped[headbang]

04-29-2012, 09:16 PM
Is the N80 clicking?

04-30-2012, 07:17 PM
Everytime I check for clicking, I hear nothing. When I run the Vag-Com readiness for the EVAP Purge Regulator, I can hear it clicking.
But when the engine is running normally, I dont hear the clicking.
I checked the Purge Regulator with 12 volt power, and it clicks open and closed normally.
I have also swapped it out with 2 different EVAP Purge Regulators and I am still having the same issue.
I also did the Boost Leak test looking for leaks, and didnt find any leaks within the engine compartment.
At this point, I am confident that my P0441 trouble code for the EVAP Regulator Purge Valve, is not the valve giving me problems, must be a leak somewhere in the rear going to the LDP or Charcoal Canister.

04-30-2012, 07:47 PM
Replace the valve regardless, if I had a nickel for every one of these damn valves I replace on a monthly basis at the dealership.. Sometimes they stick, other times there is just something horribly wrong with them internally, and electrical tests on these valves reveal squat.

04-30-2012, 07:54 PM
Mine would start clicking every once and a while but I still had p0441 & p0455. I replaced the valve and it clicks all the time an the codes are gone. Have you used a NEW n80?

04-30-2012, 07:56 PM
I also noticed a hard line that is routed along the firewall with a big pinch in it, so I removed it, cut out the pinch, and re-attached with rubber hose. Unfortunately it didnt fix the problem.

This is a picture after I cut the pinch out.

This is the section I repaced with rubber hose.

Check this picture out. It looks pretty narrow through there.

04-30-2012, 08:02 PM
No, I havent used a new n80. I used 1 from my other 01 A4, and 1 from my moms 03 A4 with the same exact issue. It fails the readiness test everytime.

05-01-2012, 11:04 AM
So my plan today is to completely removed the charcoal canister and hope I get lucky and find something obvious.

05-01-2012, 07:39 PM
I removed the charcoal canister to look for any particles, but didnt really find anything other than old jelly lookin gas.
This is a picture of the jelly looking gas, but its not in the line that goes to the EVAP Purge Reg.
This line goes to the Purge Regulator
But I decided to swap canister's from my 2 A4's just in case, but it didnt fix the issue.
While I was swapping the EVAP Purge Regulator from 1 car to the other AGAIN, I noticed the amount of vacuum on the blue car on the engine side of the Purge Regulator, but the silver car didnt have any, so I searched around the engine bay, and found what has been causing my problem.
Whoever worked on this car in the past, had some hoses backwards making the 1 way valves plug the lines up, they are located near the intake manifold.
I cant believe something so stupid caused this issue, but I have learned a lot about the EVAP system and hose routing.
Just threw this picture in cause I'm a picture whore! Had both cars rear ends up to swap charcoal canisters