My 2009 vw passat is throwing a 299 code. The car is running good what could be wrong

P0299 is typically a turbocharger under-boost condition. If your Passat has a turbocharger, then the processor is recognizing that the turbo boost provided is not what is desired. This can be due to several different causes, so you'll need to test it to find out what's going on, following procedures to diagnose this trouble code.