Took my car into the dealership for a P0457 CEL that kept popping up since they last had my car. I know it wasn't a loose cap cause because I've been clearing it and it's popped back up 3 times since after making sure the gas cap was really tight.

Shop said I need to replace the canister purge solenoid valve. Does this sound right? I don't know enough about my car to tell whether this is viable. Also, does anyone know if this is something I can do myself? The dealership wants $450 for the job (big surprise). Any help/advice would be appreciate!

TIA