a black plastic tube coming from my passenger side valve cover to the passenger side of the throttle body has a crack in it and it doesnt stay connected to the valve covers all the time. is this just to vent the engine? what is the purpose and should i buy a new one or get a crankcase breather?

 

what is the tube that goes from the back of the pass. side head too the side of the throttle body? mine is cracked do i need a new one?

 

that is part of your PCV (positive crankcase ventilation) system. this is just for emmisions. it redirects leaking gas fumes back into the TB. yes, baisically vents the engine.

oil often gets gets into this tube and thats why some people do decide to put a breather on the valve cover. there are vrious kits you can buy. do a search for some good links, i cant think of any right now

 

It's part of the PCV/CCV system. Better to leave it there, IMO.

1994-1997 RH TB to valve cover CCV hose GM p/n 10128365 .