How to create a PDF files

[eluser]mk3[/eluser]
Actually Codeigniter can do everything you can do with pure PHP, If you need some pluses no need to rewrite basic functionality, integrated formvalidation also huge amount of third party libraries etc.
For PDF part have you tried searching forums/wiki? there are many posts which relating to pdf creation:
one of them here for example: http://ellislab.com/forums/viewthread/121287/ it may not be what you are looking for but making research before asking questions should be the way