I tried searching to no avail on here so here I am. I have a P0441 code that won’t go away. When I bought the LR4 I was having issues filling the tank and would occasionally hear burping from the gas cap. Then one day the truck died on my way to work. Diagnosis determined it was the low pressure fuel pump in the tank so I replaced it and converted to the new fuel tank flange/filter. After that the truck ran fine but about a week later I got the P0441(incorrect purge flow) and P0442 (evap system small leak detected). I replaced the purge valve, charcoal canister, and evap leak detection pump. P0442 went away, but P0441 remained. Tested the new purge valve and it was a dud so I replaced it again and it is working properly now. I tried doing a smoke test by feeding smoke into the system through the disconnected purge vent line in the engine bay and almost immediately fuel started spilling from the tank vent line near the filler neck. This is as far as I have gotten so far. Is there something I am missing aside from dropping the tank again to visually inspect the lines? Also, is it normal for fuel to spill from the vent line if pressure is introduced into the system? Maybe there is a better way to smoke test the system?

Thanks in advance for any insight you guys may provide.

 

Haven't dealt with the issue on the LR4, but a lot of experience with same issue on GM trucks/Hummers and what was happening was the charcoal would get washed out of the canister and plug up the lines feeding back into the tank. We would have to remove the lines and either unclog or replace them.