I want to clean up my D16A6 intake manifold while its out of the car. Can I clean the injectors? Like blow compressed air in the reverse flow or something? And yesterday I noticed this hose is collapsed. I took it off and tried to blow through it. I figured out it has a check-valve somewhere in the system because I can only suck, not blow. Please do not make a joke. What should I really do to clean it up?