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charcoal fuel canister problems and engine performance??

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2007 Carerra S 114,000 miles


I have had a roller coaster ride of dealership attempts to find and repair a hunting idle, hesitation at low-mid RPM range and now a interrmittant intense fuel smell emmitted from right front fender area. If you refer to my previous Tech question you will see multiple parts have been replace trying to find this problem. Throttle body, MAF sensor, Crankshaft sensor, Oil seperator and now the car is back in again for all the same problems. They now have done a fuel system 'smoke' test and did not find any leaks. The mechanic now thinks the Charcoal Fuel Canister feels too 'heavy'? and thinks it might be over saturated with fuel and not purging properly?  He thinks this might be causing an OVERLY rich gas mixture 'possibly' contributing to the idle, running and performance issues AND at its extreme moments of further gas fumes induced into the canister it is then purging out to the atmosphere.

Does this all make sense? I guess the fuel smell from this over saturated canister is possible.... but what about the performance, idle hunting, hesitation... etc issues? I should also note that the problems are usually intensified more when the engine is hot.  The dealer has had the car on/off about more than I this past month. Any help is GREATLY appreciated!

thank you!

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Hi. Thank you for you reply. 

Thats the problem NOTHING of this issue has ever thrown a code. 


  That's the ongoing frustration that the dealership keep saying that every one of the parts that replaced should've each to Thrown or shown a code. 


Especially with the extent that the problems were showing themselves. 



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