Justin Gaznick

I bought the car a couple months ago and drove it 400 miles without an issue and now I have one. Car gets stuck in open loop and I get an OL Fault reading on my scanner with a P0300 random misfire code and an open injector circuit code. Originally I had a cylinder 5 misfire from a single open injector which I had replaced and it ran fine for about 50 miles, now its running rich and smells horrible.P0300 and P0200 are my current DTCs. I did get a heater circuit O2 sensor code as well but after clearing it, it came back one more time and haven't seen it since.I removed the alternator yesterday and had the voltage regulator/ alternator tested and its getting 100 amps no problem, guy said its working fine and not fluctuating. Reason I had that checked is that all my lights have been pulsing and my voltage is almost reading 18 volts and drops to around 16 and bounces around occasionally after driving (when I could actually drive it). I figured maybe my coils weren't receiving the correct voltage and causing a random misfire. Apparently I was wrong because the alternator works fine? It was previously rebuilt and is an aftermarket alternator. Im at the point of just buying a new alternator even though supposedly this one works so I can definitely rule that out as a problem. As I was removing the alternator I noticed the exciter wire had been spliced (very poorly) so I have to resplice it and try that as an option.The car ran great for 400 miles why would it randomly have this many misfires and and open injector circuit? Im getting overwhelmed and don't know where to begin to get to the bottom line. Btw car seems to run good in extremely cold weather and after it warms up misfires happen with fuel getting dumped into the engine. OL fault grrrrr somebody give me some insight! Much appreciated in advance! I already got some advice from another member just trying to get as much as possible, think I might have posted in the wrong section initially.