Front of Engine:
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DriveFast71 is correct about it being on the front of the engine, but you can't see unless you look under the intake manifold on top of the valve cover. Remove the top engine cover
The part the you are referring to on the back of the engine is the PCV Vacuum tube. If you put your hand on the back side of the intake manifold you will fell a hose that is amount 1 inch round. That is the PCV Vacuum tube. If you follow it, it will wrap around the drivers side of the engine to the front then under the intake manifold to the PCV Valve