You can specify the driver by doing the following:
On Linux, the start file is:
$ProductDir/connectors/OracleApps/start_OracleApps.sh
On Windows, the start file is:
%ProductDir%\connectors\OracleApps\start_OracleApps.bat
On i5/OS, the start file is: /QIBM/UserData/WBIServer44/QWBIDFT44/connectors/OracleApps
/start_OracleApps.sh