I have a 1997 when i go to speed up the blazer seems to not want to go. it just started this it doesnt happen all the time. i have a check engine light on saying i might have a large vaccume leak could this cause this?

 

see if the pcv hose may have popped off the pcv valve, if it's oily than replace it cause it'll just keep doing it, and its only about 2 inches long.

 

could a cat converter cause my Blazer to not want to accelerate? and sputter? It runs fine at low speeds (0-20) but any faster than that and it is junk. And where is the PCV valve?