I assume you need the O ring for the part on the intake manifold, which is 99970116340, or part #4 on the Intake Diagram. I replaced that vacuum hose that runs to the front of the car, and didn't recall seeing any O ring inside the tube. If you're talking about the white plastic C clip that secures it to the intake manifold, it's 99923051240 on the Underbody Vacuum Line diagram. It's not shown on the diagram, but pretty sure it's the C clip that secures part #22, the vacuum line, to the intake manifold.