2002 Mustang GT

My car has 69.000 miles on it. My serive engine light came on about two months ago. It started dying when I would start it. There was a hesitation and it loped like and sometimes made a popping noise when I would try and start it. Now once I got it started and driving it seemed fine. I changed the oil, new oil filter, air filter and also we replaced the fuel filter. It was throwing 6 codes before I did all this. Now it still was funny starting and I still hear a whine on the passenger side of engine. Had codes checked again. Only one was showing the camshaft sensor so I bought one amd we replaced. It starts better amd runs smoother. Oh amd we replaced the serpentine belt too. The whine is much quieter also now. But I felt it lope again and it would not start on the first turn, like it use too. So I think it’s running better amd that what we did helped it but something else is still making it run a little rough when it’s first started. Any ideas on what I should chase now?