Yea it was just the upper. I scanned it again today and it marked a new code which was P0300. I don't know if I will be able to fix this on my own. I will most likely take it to a local shop tomorrow to see if they can diagnose the exact problem and fix it. Thanks for the input guys!

Have you checked your coolant levels yet? The P0300 is now a RANDOM misfire. Quite typical of it drinking coolant.

Yes I just checked. It'* definitely sucking up coolant, there'* pretty much none there. Definitely need to take it ASAP. I wish I had time to fix it but I have a bunch of school work I need to do. Do you have any speculation as to what will need to most likely be replaced?

Its 1 of 2 gaskets. The upper or the lower manifold gasket. Either way, anyone here or shop wise will recommend replacing BOTH of them at the same time. You might as well factor in coolant elbows. We have seen this issue 1000 times here on the forum. And its ALWAYS one of those 2 gaskets, and most of the time, that one elbow breaks because its plastic.

Oh, have you checked your oil too? Let the engine sit for a few hours, then check it.

Ah ok, that makes sense. So is it most likely just the gaskets? Is there a chance it may be the upper manifold or anything more than that?

I just checked the oil, it'* just dirty but it doesn't look milky nor is it over full.

As long as your oil level stays the same, you should be good. But the engine trying to burn coolant isn't exactly good for emissions, but should a part of the gasket really fail, you could ingest so much coolant, that you hydrolock your engine. And we all know you can't compress a liquid. Bad things happen. I suggest dropping it off to a shop ASAP.

For as long as I have been on this forum(10 years now) I have never seen a warped head, blown head gasket or anything serious due to over heating that would cause the engine to consume coolant.

Need to have the coolant checked for exhaust gases. If it is a head gasket, and water is entering the combustion chamber, you risk bending a pushrod, as per the aforementioned "bad things" hydrolock. If too much water is in the combustion chamber on the compression stroke, something'* gonna give, and it ain't the water. A good shop can test the coolant and determine conclusively if it'* a head gasket. Also, take a whiff of the exhaust and see if it smells like coolant.

I hope for your sake it'* merely the LIM gasket. That'* a fix you can do yourself if you're mechanically inclined. Otherwise a shop will probably charge you a grand to do it. If it'* a head gasket, you can probably double that.

95% of the time on 3800'* the head gasket is fine and the upper manifold and lower gaskets have to be changed to the new redesigned parts. i got these all from rockauto for a little over 100 bucks, if you take it to a shop i would buy them myself and have the shop install them, that way you know you got the right things and arent going to have any more issues with it

pn;* for the dorman intake kit and aluminum elbow
https://www.gmforum.com/mechanical-1...2005-a-304071/

If you take the UIM back off to replace it you should remove the LIM and replace that plastic gasket, like the guys said, if liquid gets into your cylinders and hydra-locks, then you could possibly throw a connecting rod through the block, that would NOT be good, you'd need a new motor then.
If it is loosing coolant like you say then get to that ASAP, or it could cost you a LOT more in the future.

If you try to tackle the job yourself we have a writeup here, and I can also provide you with a video, and a thread from another site where I did my UIM/LIM for the first time.
The video is from a supercharged motor, but the removal of the LIM and all is the same.

Also, get the aluminum Coolant Elbows when you go to replace the coolant elbow, I'd not go with the plastic one again.

Well I called my local shop and the quickest time I could get it in is next Wednesday. Do I risk anything by waiting until then? The car will not be moved, it will just be sitting in front of my house until I take it to the shop.

I wouldn't be the one doing this job if I don't take it to the mechanic. Most likely a relative (who replaced my upper manifold) would. I never have tackled anything on this car other than an oil change and light stuff.