Just wanted to post my experience to hopefully help someone else in the future.

For the past couple of years, I couldn't fill the fuel tank, as the pump would shut off after about 1/10th of a gallon, and if the tank was nearly empty, would actually eject the fuel back out of the filler. I had suspected the breather/evap canister and had simply disconnected the hose from the fuel tank to the canister, which of course cured the problem, but I had to reset the CEL every few days for the air leak.

The service manual has a troubleshooting guide for the evap system which includes checking the lines for blockage by applying a low PSI volume of air. I was lazy and was using 80psi shop air, which prevented proper diagnosis for a long time - you need to stick your mouth on the lines and blow.

There is a vent line from the charcoal canister to the filler neck, and there is a plastic filter housing that fits around the filler. Mine was filled with dirt and not allowing air to escape the canister. Part number 77745-0E010 $33.

Have to pull the fuel filler neck out partially, which means removing the access panel behind the driver rear wheel, loosening the fuel pipe hold downs, and removing the rubber surround at the fuel filler.

Great post and info. Hope it never happens to me, but thanks for taking the time to share.

"For the past couple of years, I couldn't fill the fuel tank"

Years? Seriously? And I thought I was a major league procrastinator.

@Jeremy556 - how many miles and do you drive a lot on dusty dirt roads?

Hell yeah that was packed with dirt!

@Sky lots of fines/dust/sand were he lives. But yeah also curious the mileage to dirt ratio

It's dusty as hell out here. The T4r isn't my daily driver, so it sees mostly dirt roads and trails these days. Current mileage is 260k and probably 100k+ of that off pavement.

Also, I have an aftermarket rear bumper which leaves that area much more open to the elements than stock.

a couple of years of progressively getting worse to where I could barely "throttle" the gas pump and took forever to fill up! I finally replaced it yesterday. And thank you for this post as it helped me realize how easy it could possibly be to remedy, and bingo, it was a clogged charcoal filter. I was worried I'd have to drop the tank or something.

If you ever need to do this it's a pretty cheap part. See P/N in the original post. Also, it might not hurt to get the top piece as the tabs can easily break. All you need to do is remove the mudflap and plastic cover behind the driver's wheel(I didn't even need to remove the wheel), remove the bracket for the three lines, and also the bracket directly above the axle so you can move the filler tube back to remove the old filter and install the new one. No need to mess with the rubber liner inside the filler door, but you may want to remove the gas cap if it helps.

Pics....
Old vs New

Bracket(not in pic) removed from mounting bolt, also not pictured is another bracket closer to tank and above axle that made moving the tubes around a bit easier.

Pic of filler tube with filter assembly removed. Cleaned it up real nice up there! The dangling tube is the one that goes into the filter.

Super dirty around outside of the two filter halves

Breaking the old one apart... PACKED with a few years of trail dust!



I was SO EXCITED to go fill up, lol! And SOOOO relieved that THIS was the fix!!!

Careful before throwing money at this “problem”. My 2021 will auto stop the gas pump and show “past full” on the gauge, but if I trickle gas into the filler neck I can fit another $10 or 2.5-3.0 gallons into it.


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Mine does this as well. I've filled it to the very top a few times and the extra time before dropping to the top mark on the gauge is really nice. Not so sure it's good for the system? Anyway it certainly adds some miles especially if your on a trip!

Not saying this is the case, but you may be getting fuel into the charcoal canister with that method, which is not good for it. It's a box filled with charcoal sitting above the spare tire, connected between the fuel tank breather and the paper filter at the filler neck, that I replaced above.

If you have the clogged paper filter that I had, and the other poster above, you cannot fill the tank without keeping the fuel nozzle outside of the filler neck and slowly dripping fuel in, leaving plenty of room for air to escape from the filler. If you are on the reserve light and go to fill up normally, within 1.5 seconds of beginning to pump fuel, the pump will shut off and about 2/3 of the fuel you just pumped in will be shot back out through the filler and all over the pump/you/the ground.

There is a hose going from the fuel tank to the charcoal canister, which I simply disconnected. This made filling no problem whatsoever, but a CEL would set every few days because of the leak detected in the fuel evap system.

I had same problem with filling gas . After 2 seconds the nozzle just shut down.
And I throw the endoscope camera and on the gas tank inlet is something. I don’t know if this pipe should wide open or there is some flap or so
Anyone know how it should looks?
Thanks

Pretty sure that should be wide open unless you see any type of mechanical indicators that it is factory(hinge, rubber flap, etc)

There's a valve at the tank that seals the tank in a roll over, which will not allow a camera (or siphon hose) into the tank.

That makes sense!