P0446 - Regeneration Valve
 

All,

I recently purchased a 2004 GT3. It's my first porsche and I love it to death. However, I now have the dreaded P0446 code. About a month ago, the car started turning off when it became heat soaked. After cranking it for 30 seconds or so it would turn back on but it ran very poorly and rough. It did this on two separate occasions without the check engine light turning on. Now, most recently, it would not turn on after filling it up with fuel. At this point the CEL is on showing this code.

I've done quite a bit of research on here and it appears that the most likely culprit is the tank "vent valve." I've also seen it referred to as the "regeneration valve." I went onto Pelican Parts and ordered the following part #: Ventilation Valve Part #: 996-110-129-90-OEM. This was based on others' recommendations in different threads.

Here's where I need yall's help. I am not the most mechanically savvy person on the planet. I have been unable to find a DIY Guide, video etc which explains how to install this part. People have mentioned its "easy" but I need some direction. Any help would be great - Thanks!

assuming it's in the same place as a C2 it's in the fender liner on the passenger side. I had to replace it on my 996 C2 when I wasn't able to put fuel in the car.


...BUT I've never heard of it causing the car not to run right or not start.

So that is the fuel tank vent valve on the filler hose. That's at the front of the car. This regeneration valve is located near the throttle body at the rear of the car. I think I read somewhere that you have to take off the passenger right wheel in order to access it? But, again - I'm not totally sure.

Thanks for the link!

sorry I should have looked at the part number not the description.

It shows up in the Parts diagrams with the upper intake assembly but the parts diagram doesn't do a great job of laying out exactly where it sits. You are right though it appears to be passenger side of the engine but it cold be under the intake assembly. Getting to much of anything up there without at least lowering the motor down some is quite the task.

I'll peek in the garage when I get home tonight and see if i can pinpoint it on my car and give you a better feel for what it's probably going to take to get it out.

https://rennlist.com/forums/996-gt2-...ing-p0446.html

I had the same problem. It was the valve in the engine bay not the one on the filler. Pretty easy to access - it's on the left side of the intake manifold. I can't remember if the airbox had to be removed but definitely didn't need to remove any wheels. Buy a flexible clamp remover tool - makes the job a lot easier.

The part is in the mess of hoses boxed in yellow. It's the shiny smaller hose.

Thanks a lot everyone! Now I just need to cross my fingers that this fixes the problem.

How did replacing the valve go? Were you able to replace just the valve on its own ie. reuse plastic and hose that connects to it. Are you able to confirm it’s a Bosch part no 0.280.142.380 ? If so that’s the same valve that’s used in the fuel tank purge circuit. I’ve seen so many different part no’s and descriptions of this component.
im having hot start probs with my Mk1 GT3 and cant even find the part on Porsche PET !!
mike

not sure if you ever fixed your issue. I have this same problem on my 2005 C2S. I bought a new purge valve and am looking for a DIY as every thing is a very tight fit but I can’t seem to find any DIY.

that being said, yes, you have the correct part number on the actual valve but this doesn’t include the hose. If I were to do it all over again, I’d buy that part for $35 and use the old hose vs the $300 part from Porsche with the hose.

I fitted a new purge valve to fix the hot start issue which had become crippling on my GT3 mk1.
The fix did nothing so bit the bullet and had starter motor replaced… car has never started so well in all the years I’ve owned it !!! Wish I’d done it years ago, I’ve put up with the embarrassment of car not hot starting well for years!!!
hey ho.

great. Thanks for the reply!!