Replace Gas Filler Neck?

All,

I am getting the 0456 code which is "small leak detected in emissions controls" on my 2003 extended cab with 231K miles. It used to be pretty random coming on every other month or so, now I get it at least every week after resetting with my ScanGauge. Definitely smell fumes in the garage too.
Dealer smoke tested and said it was the filler tube assembly, and said it was pretty rare to get a leak there.
If I take their word for it, purchase the assembly myself to install, what is the process? Has anybody done before without removing the bed? can I just lower the gas tank a tad to get to all I need to remove and reinstall?
the dealer wants $400.00 to do the job. Ugh.............

 

really easy to take off the gas tank

unbolt gas tank skidplate (if you still have it on).
Unbolt tank strap, then the three bolts at the front of the tank (holding on to a lip on the driveshaft crossmember). This will lower the gas tank a bit, allowing you to undo the fuel line fittings

just curious, where does it leaks? on the filler tube itself? On the plate used to bolt it to the tank?

 

Just make sure your tank is EMPTY....it is NOT fun trying to fish the tube assembly up in there when the tank has gas in it. I ended up having to take the filler neck off, fish it down through the filler door and bolt it back on to the tank then jack the tank up the rest of the way. Do it the easy way...empty the tank.

 

Good question. The dealer was very non specific, just said filler tube. They actually had to pinch off all other lines to find it was leaking there. Has me wondering if it is just the plate if I can reseal that? Seems like there is not too many failure points on the filler tube, I already checked the two hose clamps, was able to get a little turn on each screw.

 

yeah, if it's just the gasket, it's easy to replace (but you'll need to take the tank off).
do you have rust on the truck? if yes, your filler tube may have a pin sized rust hole somewhere

 

While searching for something else today, this popped up. Just to bring up an old thread and in case anybody was wondering the issue was the gasket for the fuel pump assembly. Hard as rock, thanks to ethanol fuel. I removed the bed and replaced it from the top. Easy enough and issue resolved.