Console script tags garbling up non-html output (e.g. json) when in devMode
Just remove these two logging routes from your plugin's init() method in your PluginHandlePlugin.php file:

craft()-&gt;log-&gt;removeRoute('WebLogRoute');
craft()-&gt;log-&gt;removeRoute('ProfileLogRoute');


That will prevent the extra logging and profiling information to be output in the browser's console when devMode is enabled.