How do you replace fuel tank vapor valve for charcoal canister

[rhkwon]

Does anyone know where this is located and is there a tutorial on how to replace?

Fuel Tank Vapor Control Valve for charcoal canister
996-605-203-01-M244

Not sure where exactly it's located. Is it in the front passenger wheel well near the fuel filler vent valve? The symptoms I am having is gas smell in the car and lots of pressure when the gas cap is opened along with the check engine light. I forgot what code it was as I bought the part last year and not even really sure this will fix the issue. Saw a diagram showing that it is possibly located/connected to the fuel tank. How do I access this? A thread on rennlist mentioned a similiar issue that was fixed with this part. But the entire front end axle had to be dropped to access the tank? WTH? My car is a 1999 C4 btw. 
 

[JFP in PA]

1 hour ago, rhkwon said:

Does anyone know where this is located and is there a tutorial on how to replace?

Fuel Tank Vapor Control Valve for charcoal canister
996-605-203-01-M244

Not sure where exactly it's located. Is it in the front passenger wheel well near the fuel filler vent valve? The symptoms I am having is gas smell in the car and lots of pressure when the gas cap is opened along with the check engine light. I forgot what code it was as I bought the part last year and not even really sure this will fix the issue. Saw a diagram showing that it is possibly located/connected to the fuel tank. How do I access this? A thread on rennlist mentioned a similiar issue that was fixed with this part. But the entire front end axle had to be dropped to access the tank? WTH? My car is a 1999 C4 btw. 
 

 

Item #17 in diagram:

 

On 4 wheel drive cars, the front axle may be in the way.

[rhkwon]

That’s what I was afraid of. So is dropping the axle a tough job?  Would the axle be the same thing as the differential?  Sorry I’m being so stupid but suspension is definitely not my area of expertise. 

[JFP in PA]

21 minutes ago, rhkwon said:

That’s what I was afraid of. So is dropping the axle a tough job?  Would the axle be the same thing as the differential?  Sorry I’m being so stupid but suspension is definitely not my area of expertise. 

 

Yes, we are talking about the front diff, as it sits under the fuel tank..  How hard is obviously related to how well you are equipped and your mechanical expertise.

[rhkwon]

Got a chance to look under the car.  The tank is located above both front axels and the differential housing but I could not see the valve anywhere.  Looks like it is hidden somewhere between the inner fender sheet metal and the tank.  The valve is supposed to be located near the fuel filler tube but I could not see where the fuel filler tube attaches to the tank itself.   

Would the tank need to be dropped?  So not only the axles, but the differential housing itself would need to be removed to drop the tank? And not to mention the full tank of gas that's in the car.  This is getting worse and worse.  Also, since it's a C4, the tank is the "saddle" tank and not sure if this presents any additional problems.

 

Are there any tutorials on how to remove a fuel tank and all the associated parts including the fuel filler neck, clamps, etc. on a 1999 C4?

Edited April 18, 2019 by rhkwon

[JFP in PA]

1 hour ago, rhkwon said:

Got a chance to look under the car.  The tank is located above both front axels and the differential housing but I could not see the valve anywhere.  Looks like it is hidden somewhere between the inner fender sheet metal and the tank.  The valve is supposed to be located near the fuel filler tube but I could not see where the fuel filler tube attaches to the tank itself.   

Would the tank need to be dropped?  So not only the axles, but the differential housing itself would need to be removed to drop the tank? And not to mention the full tank of gas that's in the car.  This is getting worse and worse.  Also, since it's a C4, the tank is the "saddle" tank and not sure if this presents any additional problems.

 

Are there any tutorials on how to remove a fuel tank and all the associated parts including the fuel filler neck, clamps, etc. on a 1999 C4?

 

The only one that I am familiar with is from the factory service manuals, but that cannot be reproduced here as it is copyrighted intellectual property.

[rhkwon]

I saw the service manual and the detail and instructions were lacking to say the least. Now I know why the Rennlist poster paid $2000 for the replacement at his shop. 

[DBJoe996]

Get the CEL code again and post.  Before you proceed, either DIY or shop, we can help you narrow this down.  I certainly would want to know specifically and exactly that this is the problem before chasing ghosts and replacing parts.  Also, what year and model?  Other recent maintenance or problems?  There are other valves and components in the evap system to consider.  See here 

Carbon Canister

WWW.AUTOATLANTA.COM

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[rhkwon]

P0455 was the code. I posted about this problem awhile back on Rennlist and the other option was the throttle body regeneration  valve replacement   I have a good feeling that this vent valve will do the trick. It is practically hidden somewhere and I can’t find it anywhere. 

 

I have already replaced the fuel filler vent valve. 

 

Car is a 1999 C4 manual transmission with 130k on it. 

Need help with P0455 Code - Rennlist - Porsche Discussion Forums

RENNLIST.COM

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996 Forum - Need help with P0455 Code - OK, I need some help with this P0455 code that recently came up on my 1999...

 

Edited April 20, 2019 by rhkwon

[JFP in PA]

2 hours ago, rhkwon said:

P0455 was the code. I posted about this problem awhile back on Rennlist and the other option was the throttle body regeneration  valve replacement   I have a good feeling that this vent valve will do the trick. It is practically hidden somewhere and I can’t find it anywhere. 

 

I have already replaced the fuel filler vent valve. 

 

Car is a 1999 C4 manual transmission with 130k on it. 

Need help with P0455 Code - Rennlist - Porsche Discussion Forums

RENNLIST.COM

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996 Forum - Need help with P0455 Code - OK, I need some help with this P0455 code that recently came up on my 1999...

 

 

Good call on checking the code by DBJoe996; the code you are seeing is for a gross tank ventilation leak, usually caused by a bad gas cap, detached or leaking vent hose on the EVAP canister or similar hose.  It is not for that valve which would be a different code.

 

Start by looking at the seal on your gas cap and looking at the hoses for the EVAP system, which do not require dropping the fuel tank.

[rhkwon]

The gas cap is brand new and hence the woosh sound when I opened it. All the vent hoses to the canister are tight.  Not sure what else to look at. Frustrating!

 

 

[rhkwon]

Here is his post, however, unlike his issue I am able to fill the tank full of gas without any problem. 

 

Maybe it is the regenerative throttle body valve?

 

https://rennlist.com/forums/996-forum/950027-replaced-fuel-vent-valve-now-unable-to-fill-gas-tank-2.html

Edited April 20, 2019 by rhkwon

[JFP in PA]

I would be smoke testing the system before dropping the tank with the code you have.  If you take the time or pay someone to replace a part that is not the actual issue, and before confirming the actual fault, you are going to feel pretty dumb, and we don’t want that happening ?

[rhkwon]

The guru JFP speaks the truth. I must and will listen to this advice. ?

 

 

[DBJoe996]

I concur with JFP.  A smoke test is in order.  Could be your evap canister has cracked due to age/mileage.

[rhkwon]

Does the charcoal (vapor) canister go out often on our cars?

[JFP in PA]

1 hour ago, rhkwon said:

Does the charcoal (vapor) canister go out often on our cars?

 

Not often, but they do fail from time to time.