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Bumping this thread because my 06 955 w/72K mi. has recently shown the P0441 twice, a week apart, and has had two incidents of hard restarts at normal temp; the first after filling up from below 1/4 tank, the other incident (today) was with 3/4 tank after driving 120 miles. After starting in today's episode, the engine labored to hold idle; I had to torque brake and boost revs to get moving without stalling, then it drove like nothing happened fine. I've seen other threads pointing to the tank vent valve for this code.
Purge valve would be my guess. Not sure if that's what you meant by tank vent valve.
I think "tank vent" and "purge" are used interchangeably in forums for the same part. Does a failed purge valve cause hard warms starts? Easy DIY? Where is it? Its not listed with either name in my repair manual; I think its the "carbon canister solenoid valve" but have yet to find where its located in the 955 Turbo.
I guess it could. It's a simple 1-way check valve, so temp may play a roll in it's functionality. I've never replaced one, so not sure on how easy it is.
(Bump) I'm hoping that someone will confirm that an evap purge valve failure (955 Turbo) will cause hard starting for a warm engine. Since the CEL appeared after just one of two hard starts, the linkage of the code and the hard start seems dubious for me. I can replace the valve myself, but if the purge valve fail is not a reason for hard starts, I'll have to take it to the dealer (125 mi) for diagnosis. I don't have a Durometric, just an OBD scanner that reads generic codes.
Typical scenario seems to be,
Stop and shut down, fill up, won't start on first try and/or starts then stops. Runs fine once going.
I got the P0441 code again today but no starting issues at all in several stops in 90+F. No fill up. The last time was not after a fill up either; it was over an hour afterward.
I agree on the evap valve. I'll be replacing mine shortly. Symptoms include hard restart after fill up, rough running cold start, P0441 and some lean codes at idle. Can be a week before codes come back or a couple hours, codes are irregular. 955 is a 2006 V6.
Here's why I think this is such a funky problem, between the gas tank and the intake there is a carbon canister, which absorbs a good amount of fuel vapor (and sometimes even top off liquid overflow!) and needs to be relieved of its saturated load during running. When you fill the car, some fuel can get in there, and the system goes rich, when the purge valve is failed with the valve open. That too rich condition prevents it from starting easily... taking a few cranks to get the carbon canister purged enough to get closer to lambda (that 14.7:1 ratio that's so nice to burn air and fuel at). Heat may also create additional fuel expansion or evaporation into the carbon canister.
Now this valve is a frequency valve, and it ticks away (some of them are loud!) metering fuel vapors under normal conditions, but if the valve stays open, it is more or less introducing a vacuum leak into the system, but from the fuel tank (typically, there is a one way valve in the evap emissions system to prevent the tank from going under vacuum, cause that might actually stop fuel flow!) The rough running at cold start is this vacuum leak, and it helps to throw other codes.
These valves fail across the VAG range, I replaced dozens of them at the dealer, and I know they are a problem on our sister cars as well. I found this post on pelican earlier: http://forums.pelicanparts.com/porsc...ault-code.html
I have the same symptoms. Hard restart after refueling but runs fine once underway. Code P0441 on my OBD reader. We're in the Yukon on our way to Alaska so not exactly a P dealer around every corner. As long as i can get restarted each time, I'll limp along to Anchorage and then get the evaporation purge valve replaced. Anyone else?
Edit: Not sure what happened to my signature but I have a 2006 Cayenne S.
Got same error - went to gas up the car and took 2-3 minutes to fire up after filling the tank.
I see the diagrams above - but they are from a V8, mine is a V6.
Is it the same part?
Also, does anyone have a part number?
01-11-2016, 07:26 AM
P0441 Evaporative Emission System Incorrect Purge Flow Present
