I can get you specific parts to a manual but its all online at Nissan and cant be downloaded. CD Rom was rendered obsolete years ago. The engine, K9K is indeed a renault diesel engine. Its Common rail and as you will be aware the filter has loads of pipes connected to it. The filter is behind the airbox. its a twist off job with a replaceable paper filter inside. The main cause of losing power on Dci`s when you have a good fuel and air filter etc and known good fuel is the intake pipe at the back of the head, it blocks with carbon along its entire length, luckily it is easy to remove and clean out. The ~internal diameter of said pipe is around 30mm , the carbon will block it to around 10 mm !! . Try to clean the pipe, if not other issues on the dci lump are maf sensor and egr valves sticking open with the ends occasionally falling off. Regards Ben