Had a small oil leak (along with an existing coolant leak) and added an oil stabilizer to "rejuvenate" seals and gaskets. Drove around for a bit as per instructions and parked the car. The next day there was a coolant and oil leak the entire size of the car on the driveway. I have no idea what happened but losing this much fluid of any kind is probably a sign that the car is on its last legs or probably dead already. I didn't bother changing the ignition coils because a mechanic told me that it's not necessarily the coils or the spark plugs, the engine could just be losing compression.

This car was fun to drive but unfortunately I bought it in a serious state of disrepair, at a time when life just kept piling onto me and I didn't have the money to maintain it. When I took my car in for a coolant flush, the GM tech told me not to spend any money on it because it's probably going to die soon, but if I really wanted to I should swap engines and get it over with. Most of the northstars I've found were even in worse shape than mine, and the few that weren't cost almost 3x what I paid for the car.

You guys are a great community and there's tons of useful information on here, but all of it was just too little and too late considering the car's condition. I will try to find a grand prix with the LS4 if my license doesn't get yanked so I might be back. I still like Pontiacs the most.
Thanks for everything.