I just put a "test pipe" in place of my blown cat as a temporary fix until I can get a racing beat pre-silencer. For the main question, I removed the split air pipe so it wasn't just hanging. Is there anything I should do with the hose leading from the engine to the pipe in the meantime? I.E. block off the hose...ect.

 

I would block it

 

Would there be any adverse effects to permanantly blocking it off?

 

yah, you should get that blocked off asap