So my 2011 F150 with the "easy fuel" filler neck is throwing a couple of evap codes (p0455 and p1450). The purge valve seems to be functioning well, though I haven't tested the canister solenoid yet. I did the "funnel bang" about 5k miles ago but codes keep coming back. Are these easy fuel filler necks known for evap leaks? Is it worth it to just replace or do I need to cobble together a smoker? Finally, is anybody aware of a drop in replacement with normal style gas cap to eliminate this issue in the future?