What P0498 usually means
P0498 is a vent-valve control low code, so it belongs in the electrical vent branch with P0449 rather than in the pure purge-flow branch. In practice it often points toward a short-to-ground, weak feed, dragged-down control line, contaminated connector, or a vent solenoid that is loading the circuit too heavily. Because the vent side also governs how the tank breathes during refueling and monitor tests, P0498 can overlap with pump-click-off complaints and EVAP readiness failures instead of obvious engine drivability symptoms.