My 2005.5 A4 2.0T had CEL about gas cap not tight and also turbo underboost codes. Whenever I would get gas when I went to start the car after fill-up it was hard to start and chugged a bit before it would finally turn over. Took to the dealer and they said the evap canister needed to be replaced. I had this replaced 2 yrs. ago but at that time the car had different symptoms such as the gas pump would click off before it filled all they way, they said the evap canister could cause the 2 different problems. BTW I do not 'top off' my tank ever, my husband would do that but after I had the evap canister replaced the first time I told him not to do that anymore as it had caused the problem. Anyway the problem now is that when I get gas now the pump cuts off automatically as if the tank is full but it only goes to a little more than 3/4's on gauge - this is a completely new issue.

Anyone else have this problem or have an idea as to what causes this? I want some more info before I call the dealer again (I notified them the first I noticed this new issue and service manager said try one more fill up to see if it fixes itself, which it did not fix itself).

My car is out of warranty so I'm trying to stay out of the shop as much as I can.

Thanks!
Misty

 

Your car may have one or two separate problems. It is not hard to diagnose. They should first check the fuel gauge to make sure it displays correctly. They first do fuel gauge needle sweep test then read intrument panel value block of fuel sender(s) (one sender if yours is FWD, 2 senders if yours is Quattro) Read Instrument panel measure value block 4 then use ohm meter to read actual resistance of fuel sender(s). If they are matched, your fuel gauge is OK. They now can go to check for fill up problem. Most common early cut off when filling is blocking in "On board vapor recovering system" between fuel tank and EVAP canister. There is a filter mounted next to the EVAP canister. It should be always checked first.