When replacing the EVAP purge valve (valve that re-circulates the gases in the gas tank) the embedded nuts in the canister rust-weld and fall right out – especially for those in a northern climate.
To fix this, remove the embedded nuts entirely and go to your local automotive store to pick up a pair of “auto bolts” – I also used stainless steel washers.
The bolts “grip” into the plastic quite well, and hold the new purge valve in place.