Hi Steven,
You should use 11g client for 11g database server, while the miner version of client can be bigger than server version. So you can use 11.2.0.4 client to work with 11.2.0.2 database.
You can refer to SAP note 819829 for client update. As mentioned in the note, you used to create a link in order to use kernel 720 ( or btools 720).
Best regards,
James