Oh yeah thats something i didnt think about.. i did oil it and i did tug on it a little but i didnt want to break anything so i didnt really try. But what can happen if its not completely sealed? Its more than likely not up all the way if i was having those problems.

 

If the injector housing is not up into the plenum, and the O ring doesn't seal, it will leak vacuum. Not just for one cylinder, for all cylinders. Most likely will set a DTC for unmetered air or a lean condition if it leaks.