so the last 3 times i have tried filling up my car (2006 STi) at the gas station the pumps stop about 2 gallons shy of a full tank (gas gauge doesn't go to full either) no mater how many times i try to top it off it wont let me put any more in. is this something new they have done at the pumps? or is something wrong with my car?

 

So many gallons are you actually putting in?

It could be a faulty gauge/sensor.

Doubt this would make any difference, but when is the last time you did a tune-up on the car? You may want to run a bottle of that fuel injector cleaner through the car when you fill up the next time (I usually use either Chevron or Lucas brands).

Another thing to do is once you fill up, turn your car on, but do not go anywhere. Let the fuel gauge rise up before travelling to see if it makes a difference (it shouldn't, but possibly). It shouldn't take that long to do, maybe a minute or so.

Also, do you feel, smell or hear ANY other problems with the car lately? Do you know if you have changed anything about where or how you drive in last few tanks?

 

maybe I have some of your gas tank, my gauge always goes above full

There are some myths circulating about vapor in the tank/hose causing faulty readings, so maybe try the suggested filling up when its still cool in the morning.

 

are you getting the same or just about the same gas milage?

 

the car is running great no problems at all, I haven't changed anything on the car lately, and I always let the gauge rise all the way up before starting it after a fill up (usually reset miles before turning on the car), lately I been just using the car for my commute to work (about 64miles a day) first time it happened it just ignored it figuring it just stopped filling early and I didn't try toping it of second time I was concerned so I drove it 60miles then went back to another station and it took less then half a gallon before turning off and wouldn't let me top off anymore in to the tank. While I would love to drive 60 miles on less then half a gallon I know this is not right.

 

I hope that is not a bad sign? I have an 06 STi bought it used with 13k miles and I've notice it always caps around 13-13.9 gallons. I thought it was a 14 gallon tank before I started reading the manual. I get 250 to 260 miles on a full tank.

 

well you shouldn't be running it to vapors before filling up

 

13 - 13.9 is right atm im only geting 11 to go in

 

always fill up before the engine light even goes on.

 

fixed

 

It could be a clogged or bent air vent tube located near the filler neck. If it's partially blocked, the nozzle at the gas pump will shut off prematurely. I don't have the '06 STI manuals, but the Engine service manual would list the procedure of how to remove or replace it.

 

Are you always filling up at the same station/pumps or different ones? Some pumps will shut off prematurely, it may be worse with some vehicles than others. If you're always using the same station try a different one.
When this happens consistently regardless of where you fill up, it's usually a problem with the evap system, either a filler tube vent as Wingless said or a tank vent.

 

Hmmm.....If you are only putting in 11 gallons where is the needle showing on the Gas Gauge before you fill up? At Empty? Above the Empty Line? Below the Empty Line?

When I had my '95 Nissan 240sx, I used to be able to not just have the needle below Empty, but it would be BURIED below the Empty line before I was truly out of gas. That car has a 17 gallon tank and if I filled up at the Empty line, I would only be putting in around 13 gallons (give or take a gallon).

I would say it might be time to start experimenting and see how far you actually can go to see where the needle is actually reading before you really run out of gas. I am not saying to run out (that is all bad), but just experiment and see if it is just that your needle float is not slightly misaligned causing you to THINK you are out of gas, when in reality you still have another few gallons to go before you are truly out of gas.