My 2005 Z has almost 159k miles on it. I regularly fill it up from "empty" with about 15gallons of fuel. A few weeks ago I was double-checking the actual tank size as was surprised to find that it holds 20gallons (not even my Passat or V70R have a tank that big...compared to everything else in my "fleet", only our '05 Ram Cummins has a larger tank at 34gallons).

So, I decided to extend my time between fill-ups and run way past empty. This got me over 400miles from the tank, and then when I went to fill up I encountered new issues...

1) When I filled up from way past empty, I could only get ~14gallons to go in the tank, and then it struggled to add any more. I gave up and left it ~3/4 full.
2) I used to have a gas smell from right after I filled up until I drove through a few gallons of gas. The gas smell is now WAY more prominent.

I do have the CEL lit on the dash (it's been that way since I bought it, essentially) - the code is 0455 EVAP Leak. Reading on different issues, it looks like my Z probably could have had the EVAP hose TSB/recall done a few years ago, but the previous owner and I missed the window for the extension (15yrs and 150k miles).

So, I'm planning to replace the fuel tank gasket (I've read here that those tend to age and allow a fuel smell with a full tank), and then it looks like I'll have to replace EVAP hoses, as well. But is there anything else I should expect to find/replace?

Now is the time where I should finally pick up a diagnostics tool, too. I have been eyeing the NissanDataScan SW for the PC. I use similar tools for my VW, Volvo and Ford via a laptop interface, and this seems like a decent solution (feedback on this is appreciated).

I'd appreciate any input from BTDT experience resolving a similar issue to the symptoms I describe. Thanks!

 

My tank states empty when there is about 6-8 gallons left in the tank. The sending units are known not to be accurate on the z's
You should look at the vent for the tank. I'd be very surprised if it's the fuel tank gasket