Take care when you are pushing the pipe back in, I dislodged the new o-ring which then disappeared into my intake manifold never to be seen again!

 

I'm also worried the tip of the plastic tube may have broken off, and if I just push the tube home, that piece will get inhaled. I just might take the TB off before doing anything, just to be sure. I think a mechanic may have yanked the tube out during an engine swap, broken the plastic retainer and just had the O-ring holding the tube in place after the installation. I'll need to confirm this later, but that might make things easier.