After the part f the quest "There Stand the Grass", where you light the fumes ED-E went unconcious but woke up then started to follow me as per usual. After about 2 more hours of playing I could not find ED-E, it says he is at Vault 22 but I have searched extensively and not finding him even though it say he is there. Any help to get him back would be much appreciated.

Thanks if anyone has experienced the same or similar please respond

I have the same problem. He left Vault 22 with me, then he was not there but I still had his perk. When I went to Lucky 38 rex was not even there anymore. I started Dead Money DLC which said ED-E was sent to Primm but after I finished the DLC he was not at Primm and rex is still gone.

-.-