I had that code as well. Replaced the gas cap and problem went away. Also my gas cap "looked" ok.
There cheap as well, I'd try that first.

 

there is a solenoid under the battery tray. But you really need to smoke it...

 

Def. get a smoke test, will cut down most of the guessing game

 

We are looking for the location on the car of the sensor pictured. This should be the fuel tank pressure sensor.
Tim

 

It is under the battery tray.

 

Thanks Tim.

Now we have an idea how the system goes together we can do a leak test (once we figure out how to tie in; any suggestions for a couple of amateurs?).

If there really is a leak vs an intermittent component we'll be looking to pressure with helium and use a sniffer (we have these available to us). The DME manual is talking about using a hydrocarbon sniffer others talking about smoke testing. With a small leak we're thinking it will be tough to see smoke?

 

Sad to say but the problem is still here.
I have replaced one solenoid valve on the engine that controls the vacuum to the charcoal canister and the two valves in the manifold in the right front fender. I bought a Dura metric and can see the tank pressure difference is a positive when it should be a negative. A friend has brought his car over and I have been to his place comparing values from his car to mine. I have vacuum at the charcoal canister and the canister flows air threw all three pipes but I have pressure in the tank. My canister is different from the drawings in pep. I have attached a picture. Any help here??? Please. J

 

found the evap leek!!! It was the seal on the line conecting to the flapper (orange nipple)valve seen in a picture in this post on page one. It was luck that I found it. A friend was looking at the durametric while I was pulling on fittings and the tank pressure diff jumped.

 

As luck would have it...or NO luck would have it. This car seems to have found itself another evap leak before I could get everything to a ready state.The fitting that I fixed still looks good. Now the car has found something else to leak in the evap system. Is there any inde Porsche guys on here that really know these cars. I'm tired of replacing this and then that to see if it works...and so is my wallet.

 

Another update...this seems never ending. I was using the Durametric with the car running watching the tank vacuum. In the attached picture you will see a blue (check?) valve to the left of the shock. I was snapping my finger on it and it would vibrate or kind of a shuttering sound and I would see the car try to pull a vacuum. Then is would stop in a second or two. Is this a check valve and does that seem to be a failure mode?

Tim

 

I went to the dealer and in a week they figured it out and fixed it. It was the housing of the flapper valve in the fill tube. It had a very small crack that was leaking just here and there. Thanks to everyone here for their help.

Tim

 

Was the flapper valve part #12 in the first diagram?

Sam

 

Yes. It had a hair line crack that leaked here and there.

 

anyone have a pointer on a 997 Turbo? I'm getting tired of this code and the new gas cap didn't help. Anything I can change or alter myself to see if the problem goes away?