BBCode Template Replacement

[Black Snow]

I am wondering why the bbocode templates are different in respect the replacing the template with a plugin. I tried this using the hook template_render_output like I normally do with this plugin:

if ($this->template == 'bbcode_code')
    {
        $this->template = 'new_bbcode_code';
    }

It doesn't want to replace the bbcode template with my new template. Anyone know why?