So the gas gauge stopped working correctly over the winter and now in addition to that the DIC is telling me "Check the gas cap". I put a new GM cap on, the filler neck was rusty so I sanded it and applied some oil to the lip of the neck and the cap.
DTC code is 440 and I keep getting informed to check the gas cap.
Has anybody had these failures be related or are they two separate issues? The car has 120k miles on it.