my truck is running sluggish so i was going through it and noticed that the tube going from the throttle body to the drivers side valve cover, at the bottom where it goes into the valve cover, theres some oil that seeps out when i wiggle it. does that mean the grommet is bad and can that make my truck run sluggish?

92 chevy silverado 5.7 tbi.

it runs a little rough at idle when its cold but runs fine when it runs for a sec.
the idle rises a lot when i turn my defrost on.
kinda bogs down when its in low gear when cruising.
wants to bog/flood when i press on the gas in low gear when in the city (35-40mph).

ive replaced EGR, map, temp sensor, o2 sensor, fuel filter. iac, tps etc. tests fine.

could it be the grommet?? ugh