Greetings all,

About 2 or 3 weeks ago, I noticed my car would act up pretty bad, but only say one day out of the week. All the rest of the days it was fine, but there always seemed to be that magical day.
It feels like a pretty bad misfire, and the car'* RPMs would drop from 900 to like 400 ish and stall in park, so I assumed it was (another) bad coil pack. I checked them all with the ohm meter, and they seem fine. Checked all my plug wires for visible damage, or lack of being hooked up right etc. Again, all seemed right.
I read that a vacuum leak could cause my issues, and I did a rough visual check (without removing air box etc), and from what I seen, all looked well.
I began to just put up with it, because I couldn't find anything overly suspicious. The other day our temps here dipped to about -46C with the wind chill, and bonne was not a happy camper. The car began to do the rpm drop that causes the in park stalling while I was at red lights and other stops, although it never stalled.
Now the car runs kinda crappy all the time. It'* odd, but it seems to hesitate a little, but it still has a lot of power after the short lag in response. I'm just not sure where to look next, I have no garage at my place, and I'm just looking to find that member that will go omfg that'* exactly what happened to me!!!!
Any Info would be great.
Thanks!!

What have you done to your car recently, any tuneups, fuel filter change? You could start off by cleaning your MAF sensor.

Kind of sounds like a vacuum leak. Spray some carb cleaner around the vacuum lines. Don't forget to spray around the EGR (this is what I think it is), also around the injectors and the LIM and UIM gaskets.

Ok, well Mike, I have not recently done anything major. It had a new fully rebuilt motor put in that had about 75k on it, and i have changed the fuel filter (3 or 4 months ago), and the MAF at about that same time was cleaned well with MAF cleaning spray. When the motor went in, it got new plugs and wires, but to my regret I cheaped out on new coil packs. I ran into issues with that, but I had 3 spares, so in the end it worked ok.
Dan, I'm kind of thinking its vacuum also, but I dont have carb cleaner handy (haven't had a carbed car in years). Is there anything else a guy can use, or should I just go grab some?
Also as a quick update. I drove in to work today, and on the highway the car was hesitant and running sort of crappy, but at one point it almost seemed to overcome its problem and run normally. When I 1st started it up today (about -11 (20 with wind)) the motor was sucking so much air, it sounded like a jet engine. That went away when it warmed up, and to be honest, that might be how it acts when its cold out, and I just run back to the house to quick to care.
Mondays are a quiet day at work, so I plan to use a few smoke breaks to do a little bit more in terms of trouble spotting, so if anyone has any ideas that could be pulled off with a small amount of tools at work, lets hear em.
Thanks everyone who has chimed in!

Hard to tell until we can eliminate the possibility of a vacuum leak. I'm also starting to wonder about your fuel pressure. Considering the fact that we both have identical cars, and I have suffered the ground bus issue(https://www.gmforum.com/showthread.php?t=278980) though I only experienced complete loss of power to the fuel pump. It'* possible that you could be getting low power to the fuel pump and experiencing the current symptoms.

Well my dad bought a fuel pressure tester that we never bothered even unwrapping from its package. We thought that was an issue a while back, but we fixed that without messing with the fuel system. I cant say that it isn't a problem, but in the recent past its proven to not be.
This happened slowly. One day id drive it, and it would act up just slightly (enough to be noticed), but then for 3,4, sometimes 6 or 7 days, it would run like a top!
Then it started to drop rpms in park only and stall if say I went to the store, put it in park, then it would stall out. It would start right back up np, but now its starting to do the RPM shuffle when I'm on the brakes at a red light. Today, for example, it was running ok as far as RPMs go, but it would kinda kick from time to time.
(running fine, running fine, running fine---kick kick--running fine again).

You experience more when sitting on the brakes? Vacuum leak somewhere, booster?

It use to just be a in park issue, and it drove nicely, but yes, now when i am on brake at a light, it kicks a little and fights with me.
BTW lol @ your bonne survey. Sounds a lot like mine just with less ammo, and more luck at the junk yard. I cant find scrap bonne'* here for some reason, which is weird, seems like they die enough. Should be plenty! Wahaha

Ok,
I just went out to tinker around. EGR metal tube is fine at a glance. The massive sucking sound is gone, and the stupid thing is running like a top again. Took it for a drive around the block.
Frustration!

The sucking sound is your IAC valve, it regulates the amount of air during warm up. It goes away after awhile. A malfunctioning IAC/bad connection could also cause these symptoms.