Help with P0456 / P0443 codes? 2007 hemi 5.7, 1/2 ton.

[Johnnymac2k6]

For the better part of a decade, I've chased these codes on my truck. If the codes are cleared, they will stay off for anywhere from 6 months, to 6 minutes. Sometimes instantly pops on startup, and goes back out by the next. Sometimes pops in middle of an hour drive. Sometimes the engine light will shut itself off, and not come back on for months.


I've thrown more than several gas gaps, gas tank evaporative control valves (4861961AD) , engine bay evap valves (4891739AA), and most recently, full pressure smoke test checking for leaks between the fuel tank, and the engine bay. The parts have been OEM. not just amazon specials.

This truck simply has no leaks / cranks / bad lines. The only smoke that would release anywhere, is after enough pressure, the 4861961AD valve on the tank would release and let a small amount vent out the firewall routed vent.

no leaks / cracks in charcoal canister
no leaks in the "filter" / black canister on the frame
no leaks in fill neck.

the codes are popping more frequent now, and i'm not sure if thats summer weather, or what.

I don't drive this much, but it is annoying.

Does anyone have any insight?