I picked up an 04' 470 a few weeks back. Truck is very clean but had a few small issues. Been knocking them out one by one when I had time. The last one was an issue with filling the fuel tank. The pump would click off after about a half gallon and it would require you to slowly fill the tank and it would take forever. Did some research and figured it was one of 3 issues
Fuel vapor solenoid
EVP canister
Overflow flapper inside tank

Did a quick ebay search and found a canister with vapor solenoid as a combo for $70. Picked it up and started the swap today.. as I was removing the bolts to remove the canister I see that one of the vapor vent hoses (runs from canister to fuel vapor solenoid) was completely pinched (looks like someone touched it with a shop lamp, maybe when doing suspension swap out). See pic below
The hose that lexus uses is akin to plastic wire loom.
I cut out the burnt section and mended the hose. Took it to the gas station and it worked!!
Here is a pic of the burnt hose. The exhaust is close to the hose but not close enough to cause this.
Thought I'd post as this is one of them odd issues that you rarely come across.

 

Nice find - would not have thought that was the cause.

Chip H.

 

where is that solenoid located? The only hoses i see from the pic you shared go from the canister to the filter and from the canister to the gas tank and I don't see a solenoid anywhere...