Running lean from intake vacuum leak?
 

How much damage would I have done if I just discovered that there might have been a small vacuum leak where the PCV hose connects to the intake large side nipple?

I have stillen gen 3's installed and for those nipples I just tossed on some rubber hoses with no clamps to the Stillen nipples, so the hose was just resting on the nipple loosely with enough room for unfiltered and unmetered (this is after the MAF sensor) air to get into.

It's been like this for the past half year at least.

How much damage could I have done to my engine with possible lean conditions due to intake vacuum leak? I don't race but I do run it hard here and there.

Don't think you did any damage. Guys have run like that for a year without knowing it. After you fixed it. The car still runs good?

that's reassuring to hear. I'm hoping that I didn't make the piston rings looser or anything bad like that.

Yup I temporarily put some duct tape to try to seal the tube and now I started hearing the intake whistle noise for the first time in a long time :ugh2:

that means that at WOT the intake was sucking air from the little hole. there's little sand debris flying around in the bay and also unaccounted air going into the cylinders making it run lean. Lean + sand.